Historical variation and trends in storminess along the Portuguese South Coast

This work investigates historical variation and trends in storm climate for the South Portugal region, using data from wave buoy measurements and from modelling, for the period 1952 to 2009. Several storm parameters (annual number of storms; annual number of days with storms; annual maximum and mean...

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Bibliographic Details
Published in:Natural Hazards and Earth System Sciences
Main Authors: L. P. Almeida, Ó. Ferreira, M. I. Vousdoukas, G. Dodet
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2011
Subjects:
geo
Online Access:https://doi.org/10.5194/nhess-11-2407-2011
http://www.nat-hazards-earth-syst-sci.net/11/2407/2011/nhess-11-2407-2011.pdf
https://doaj.org/article/5f2fd8f2bcfd4e0c95f36a12f6d00f1e
Description
Summary:This work investigates historical variation and trends in storm climate for the South Portugal region, using data from wave buoy measurements and from modelling, for the period 1952 to 2009. Several storm parameters (annual number of storms; annual number of days with storms; annual maximum and mean individual storm duration and annual 99.8th percentile of significant wave height) were used to analyse: (1) historical storminess trends; (2) storm parameter variability and relationships; and (3) historical storminess and its relationship to the North Atlantic Oscillation (NAO). No statistically significant linear increase or decrease was found in any of the storm parameters over the period of interest. The main pattern of storm characteristics and extreme wave heights is an oscillatory variability with intensity peaks every 7–8 yr, and the magnitude of recent variations is comparable with that of variations observed in the earlier parts of the record. In addition, the results reveal that the NAO index is able to explain only a small percentage of the variation in storm wave height, suggesting that more local factors may be of importance in controlling storminess in this region.