Assessing wavestorm hazard evolution in the NW Mediterranean with hindcast and buoy data

Ortego, M. I.; Tolosana‐Delgado, Raimon; Gibergans-Báguena, José; Egozcue, J. J.; Sánchez‐Arcilla, Agustín

doi:10.1007/s10584-011-0388-y

Cited by 11 publications

(15 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(3) is essentially that proposed in Ortego et al (2012) for ocean waves, although a bit simpler due to the fact that in the present data set there is no overlapping in time between the hindcast and buoy observations. Once the model for occurrences in time is specified, its capabilities and limitations can be discussed.…”

Section: Occurrence Of Wind Eventsmentioning

confidence: 72%

“…The illustration series in this contribution shows no overlap between model hindcast and measured data, and therefore the proposed model does not account for it. An analogous model for overlapping series was presented by Ortego et al (2012), where it was shown that the results are not significantly altered when accounting for overlap, albeit for significant wave height data.…”

Section: I Ortego Et Al: Bayesian Trends Of Extreme Windmentioning

confidence: 91%

“…When interruptions of observations are present, as is the case in the buoy data set, some time differences τ j − τ j −1 do not correspond to elapsed times between consecutive events; these time intervals are ignored in the likelihood (see further details in Ortego et al, 2012), i.e. the likelihood (Eq.…”

Section: Occurrence Of Wind Eventsmentioning

confidence: 99%

“…In order to take into account the restriction ξ < 0, other parameterisations of GPD in the Weibull domain of attraction have been proposed (Ortego et al, 2010(Ortego et al, , 2012; we adopt here the parameterisation in Ortego et al (2012). We use…”

Section: Event Magnitude Modelmentioning

confidence: 99%

“…changes cannot change it, and it is therefore constant over time (Ortego et al, 2012). We also assume that µ may be different for hindcast data and data observed at the buoy.…”

Section: Reference Gpd (Param Given)mentioning

confidence: 99%

See 4 more Smart Citations

Bayesian trend analysis of extreme wind using observed and hindcast series off the Catalan coast, NW Mediterranean Sea

Ortego

Egozcue

Tolosana‐Delgado

2014

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract. It has been suggested that climate change might modify the occurrence rate and magnitude of large oceanwave and wind storms. The hypothesised reason is the increase of available energy in the atmosphere-ocean system. Forecasting models are commonly used to assess these effects, given that good-quality data series are often too short. However, forecasting systems are often tuned to reproduce the average behaviour, and there are concerns on their relevance for extremal regimes. We present a methodology of simultaneous analysis of observed and hindcast data with the aim of extracting potential time drifts as well as systematic regime discrepancies between the two data sources. The method is based on the peak-over-threshold (POT) approach and the generalized Pareto distribution (GPD) within a Bayesian estimation framework. In this context, storm events are considered points in time, and modelled as a Poisson process. Storm magnitude over a reference threshold is modelled with a GPD, a flexible model that captures the tail behaviour of the magnitude distribution.All model parameters, i.e. shape and location of the magnitude GPD and the Poisson occurrence rate, are affected by a trend in time. Moreover, a systematic difference between parameters of hindcast and observed series is considered. Finally, the posterior joint distribution of all these trend parameters is studied using a conventional Gibbs sampler. This method is applied to compare hindcast and observed series of average wind speed at a deep buoy location off the Catalan coast (NE Spain, western Mediterranean; buoy data from 2001; REMO wind hindcasting from 1958 on). Appropriate scale and domain of attraction are discussed, and the reliability of trends in time is addressed.

show abstract

Section: Occurrence Of Wind Eventsmentioning

confidence: 72%

Section: I Ortego Et Al: Bayesian Trends Of Extreme Windmentioning

confidence: 91%

Section: Occurrence Of Wind Eventsmentioning

confidence: 99%

Section: Event Magnitude Modelmentioning

confidence: 99%

“…changes cannot change it, and it is therefore constant over time (Ortego et al, 2012). We also assume that µ may be different for hindcast data and data observed at the buoy.…”

Section: Reference Gpd (Param Given)mentioning

confidence: 99%

See 3 more Smart Citations

Bayesian trend analysis of extreme wind using observed and hindcast series off the Catalan coast, NW Mediterranean Sea

Ortego

Egozcue

Tolosana‐Delgado

2014

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra‐tropical cyclone

Naylor

Stephenson

Smith

et al. 2016

Earth Surf Processes Landf

View full text Add to dashboard Cite

Extreme wave events in coastal zones are principal drivers of geomorphic change. Evidence of boulder entrainment and erosional impact during storms is increasing. However, there is currently poor time coupling between pre-and post-storm measurements of coastal boulder deposits. Importantly there are no data reporting shore platform erosion, boulder entrainment and/or boulder transport during storm events -rock coast dynamics during storm events are currently unexplored. Here, we use high-resolution (daily) field data to measure and characterize coastal boulder transport before, during and after the extreme Northeast Atlantic extra-tropical cyclone Johanna in March 2008. Forty-eight limestone fine-medium boulders (n = 46) and coarse cobbles (n = 2) were tracked daily over a 0.1 km 2 intertidal area during this multi-day storm. Boulders were repeatedly entrained, transported and deposited, and in some cases broken down (n = 1) or quarried (n = 3), during the most intense days of the storm. Eighty-one percent (n = 39) of boulders were located at both the start and end of the storm. Of these, 92% were entrained where entrainment patterns were closely aligned to wave parameters. These data firmly demonstrate rock coasts are dynamic and vulnerable under storm conditions. No statistically significant relationship was found between boulder size (mass) and net transport distance. Graphical analyses suggest that boulder size limits the maximum longshore transport distance but that for the majority of boulders lying under this threshold, other factors influence transport distance. Paired analysis of 20 similar sized and shaped boulders in different morphogenic zones demonstrates that geomorphological control affects entrainment and transport distance -where net transport distances were up to 39 times less where geomorphological control was greatest. These results have important implications for understanding and for accurately measuring and modelling boulder entrainment and transport. Coastal managers require these data for assessing erosion risk.

show abstract

Projected future wave climate in the NW Mediterranean Sea

Casas-Prat

Sierra

2013

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

[1] Projected future regional wave climate scenarios at a high temporal-spatial scale were obtained for the NW Mediterranean Sea, using five combinations of regional-global circulation models. Changes in wave variables were analyzed and related to the variations of the forcing wind projections, while also evaluating the evolution of the presence of the different types of sea states. To assess the significance of the changes produced, a bootstrapbased method was proposed, which accounts for the autocorrelation of data and correctly reproduces the extremes. For the mean climate, relative changes of H s up to 610% were obtained, whereas they were around 620% for the extreme climate. In mean terms, variations of H s are similar to those associated with wind speed but are enhanced/ attenuated, respectively, when fetch conditions are favorable/unfavorable. In general, most notable alterations are not in the H s magnitude but rather in its direction. In this regard, during the winter season, it is interesting to note that the significant deviations between the results derived from the two global circulation models are larger than those between regional models. ECHAM5 simulated an enhanced west wind flow that is translated into more frequent W-NW waves, whereas the HadCM3Q3 global model gives rise to the east component, which contributes to a higher intensity and number of storms coming from such a direction and directly affects the wind-sea/swell distribution of coastal stretches that face east, like the Catalan coast. Different patterns of change were obtained during the summer when a common rise of NE-E waves was found.

show abstract

Assessing wavestorm hazard evolution in the NW Mediterranean with hindcast and buoy data

Cited by 11 publications

References 31 publications

Bayesian trend analysis of extreme wind using observed and hindcast series off the Catalan coast, NW Mediterranean Sea

Bayesian trend analysis of extreme wind using observed and hindcast series off the Catalan coast, NW Mediterranean Sea

Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra‐tropical cyclone

Projected future wave climate in the NW Mediterranean Sea

Contact Info

Product

Resources

About