Winter wave climate, storms and regional cycles: the SW Spanish Atlantic coast

Abstract

Climatic change-related impacts on coastal areas became an important issue in past decades and nowadays threaten many human settlements and activities. Coastal hazards are linked to flooding and erosion processes associated with sea level rise and the increased strength of hurricanes, cyclones and storms. The main aim of this work is the characterization of coastal storms in Cadiz (SW Spain) and the determination of their recurrence intervals and relationships with several regional cycles. Storm characterization was carried out using the Storm Power Index (Dolan and Davis, 1992) and five classes were obtained, from class I (weak events) to V (extreme events). Storm occurrence probability was 96% for class I (i.e. almost one event per year) to 3% for class V. The return period for class V was 25 years and ranged from 6 to 8 years for classes III and IV storms, e.g. significant and severe events. Classes I and II showed a period of recurrence ranging from 1 to 3 years. Stormy winter seasons were 2009/10 (12 events), 1995/6 and 2002/3 (with 10 events each) and 1993/4 (8 events). Approximately 40% of the change in monthly wave data and storminess indices was related to several teleconnection patterns, the most important drivers of change being the Arctic Oscillation (AO), 21.45%, and the North Atlantic Oscillation (NAO), 19.65%. It is interesting to note that a great number of storms, larger storm duration and higher values of Storm Power Index were only observed when neutral to strong negative NAO and AO phases occurred at the same time (89 storms and 3355 h) and/or when there was an abrupt change of NAO and AO phases, i.e. they moved from a positive to negative phase without passing through a neutral phase. The results obtained in this work have wider applications for ocean and coastal management. It is suggested that methodology used can be easily applied in different areas where wave buoy data are available. In the same way, information obtained with this kind of work constitutes the first step in the development of coastal protection plans to preserve socio-economic activities from the impact of severe storm events.

Extreme Wave Storms and Atmospheric Variability at the Spanish Coast of the Bay of Biscay

“…One example is the use of unsupervised clustering algorithms to group wave data into a few sea-state modes, each of them being associated with contrasted values for wave height, period, and direction [38,39]. Other approaches [40,41] that focus on the potential effect of storms upon coastlines, categorized storms into several classes on the basis of the energy content for each storm, but the link between wave storminess and large scale circulation is less evident than in our approach.…”

Characterization of storm events along the Gulf of Cadiz (eastern central Atlantic Ocean)

“…In order to prevent such natural hazard impacts and associated economic and human losses, coastal managers need to know the intrinsic littoral characteristics and sensitivity. These are determined using information on the physical and ecological coastal features, human occupations, and present and future wave climate trends (Cooper et al , ; Komar and Allan, ; Phillips and Crisp, ; Rangel‐Buitrago and Anfuso, , , ). The characterization of wave climate and especially storms represents a basic need to account for their temporal patterns and characteristics.…”

“…1054046 point and Cadiz offshore buoy REDCOS 1320. Rangel‐Buitrago and Anfuso () and Rangel‐Buitrago and Anfuso () categorized coastal storms respectively along part of the Atlantic side of Andalusia [by the use of HIPOCAS (Hindcast of dynamic Processes of the Ocean and Coastal Areas of Europe) data] and at Cadiz (by the use of offshore buoy data) into five classes according to the Dolan and Davis () index. Ribera et al (); Del Río et al () and Plomaritis et al (, 2015) investigated storm thresholds, characteristics and variability on the Spanish coast of Cadiz Gulf.…”

Determinación y caracterización de situaciones de temporal marino e inundación costera por rebase del oleaje en San Andrés, NE de Tenerife (1984-2014)

“…A fin de identificar situaciones en las que el comportamiento del oleaje difiera con claridad del régimen medio anual, se ensaya con los percentiles 95 y 99 de los promedios diarios de la altura de la Hs Rangel & Anfuso, 2013;Lionello, s.f), que arrojan un valor de 2 y 2,6 metros, respectivamente. En función de estos resultados, se opta por el registro del percentil 99, puesto que refleja el 1% de los eventos más extremos de la serie estadística y se estima más representativo de los valores extremos.…”