Response of the North Atlantic wave climate to atmospheric modes of variability

Abstract

This study investigates the relationship between the wind wave climate and the main climate modes of atmospheric variability in the North Atlantic Ocean. The modes considered are the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, the East Atlantic Western Russian (EA/WR) pattern and the Scandinavian (SCAN) pattern. The wave dataset consists of buoys records, remote sensing altimetry observations and a numerical hindcast providing significant wave height (SWH), mean wave period (MWP) and mean wave direction (MWD) for the period 1989-2009. After evaluating the reliability of the hindcast, we focus on the impact of each mode on seasonal wave parameters and on the relative importance of wind-sea and swell components. Results demonstrate that the NAO and EA patterns are the most relevant, whereas EA/WR and SCAN patterns have a weaker impact on the North Atlantic wave climate variability. During their positive phases, both NAO and EA patterns are related to winter SWH at a rate that reaches 1 m per unit index along the Scottish coast (NAO) and Iberian coast (EA) patterns. In terms of winter MWD, the two modes induce a counterclockwise shift of up to 65 ∘ per negative NAO (positive EA) unit over west European coasts. They also increase the winter MWP in the North Sea and in the Bay of Biscay (up to 1 s per unit NAO) and along the western coasts of Europe and North Africa (1 s per unit EA). The impact of winter EA pattern on all wave parameters is mostly caused through the swell wave component.

Climate control on late Holocene high-energy sedimentation along coasts of the northeastern Atlantic Ocean

“…Within the Pertuis Breton, the NAO and EA/WR patterns respectively account for 25.2 and 20.6% of the winter (December to February) longshore sediment transport variability, while the contribution of EA pattern is minor (3.6%) and that of SCAN is not significant. Longshore sediment transport increases with positive NAO and negative EA/WR conditions (Poirier et al, 2017), both being associated with higher offshore and nearshore waves in the area (Martínez-Asensio et al, 2016).…”

Statistical modeling of interannual shoreline change driven by North Atlantic climate variability spanning 2000–2014 in the Bay of Biscay

“…This would require further calibration, as the best-fit coefficients are site-specific. For instance, Martínez-Asensio et al (2016) demonstrated that while NW European Atlantic coasts experience above average wave energy conditions during high winter NAO+, the S European Atlantic coasts undergo the opposite (and vice versa for high winter NAO-). This in turn drives opposite shoreline response, as for instance during the winter 2009/2010.…”

“…However, model skills strongly depend on the availability and quality of wave data. The characteristics of waves reaching the coast depend strongly on remote surface atmospheric circulation (e.g., Bacon and Carter 1993;Young 1999;Woolf et al 2002;Le Cozannet et al 2011;Charles et al 2012a;Martínez-Asensio et al 2016). Because waves are the primary driver of shoreline change along most coastlines, interannual shoreline variability is expected to be related to interannual large-scale atmospheric dynamics.…”

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

“…Although it is widely accepted that large wave storms in the Atlantic Ocean are a direct consequence of the passage of extratropical cyclones, the details of this relationship at the regional scale need to be clarified, since it is not known whether the magnitude of the event is more closely related with the track or the depth of the forcing cyclones. Additionally, these cyclones usually propagate along preferred trails, so-called storm tracks, and the phases of enhanced or reduced storminess along European Atlantic coastlines are modulated by hemispheric-scale circulation patterns, known as teleconnections [14][15][16].…”