Abstract:
Resumo:
Extreme sea levels along the Atlantic Iberian coast are determined through the
development and application of a numerical model for tides and surges, followed
by a statistical analysis of the model results. A recent statistical method is
assessed using 131 years of data from the Brest tide gauge, and the number of
years of data required for an accurate statistical analysis is estimated. The
statistical method is extended to consider tide–surge interactions, but they are
shown to be small in the study region. The model covers a large portion of the
NE Atlantic, with a 250 m resolution in the Portuguese shelf. In the Iberian
shelf, root mean square errors of tides are of the order of 5 cm, and extreme
sea levels are underestimated by about 10 cm. Differences between sea level
statistics obtained from model output and observations are of the order of 5 cm
in the study region. Simulation of tides and surges between 1980 and 2010,
followed by a statistical analysis of the results, provide the extreme levels
along the Iberian Atlantic coast for different return periods. Results reveal
the increase of extreme sea levels from south to north and the importance of
local effects.