Analysis of the Voyager storm

International Journal for Numerical Methods in Engineering, 1989

We present the results of the implementation of an advanced wave model in the Adriatic and in the Mediterranean Sea. With respect to the first and second generation models, the new approach does not accept any a priori assumption on the spectral shape of the wind waves, this being determined uniquely by the dynamical equilibrium of the various source functions. These include the generation by wind, non-linear interactions and the dissipation due to whitecapping and to bottom friction.The Adriatic is characterized by highly variable wind regimes. Several storms have been hindcasted, testing the model in the various possible meteorological conditions. In this paper we focus our attention on a particular storm that allowed us to verify the shallow water behaviour of the model. For the Mediterranean we concentrate on a heavy storm that occurred in February-March 1986 in the Sicily Channel. The very good results obtained in these two highly different conditions prove the effectiveness of the physical approach to the numerical description of the wind waves evolution.

An advanced, third-generation wave model has been repeatedly applied to the Mediterranean Sea. We have studied the accuracy of the results and the factors that control it. The grid resolution, when less than 0.5 ø , is shown to have in general negligible effect in the open sea. The related accuracy of description of the coastal border can have a relevant effect on the wave field on the side and on the wake of the coastal details, for a distance of a few grid points. The difficulty of correctly evaluating the wind in the Mediterranean basin is dramatically shown by comparing the results obtained using wind fields with different resolution. The crucial role of the orography in shaping the wind fields and the need for higher-resolution models is established. It is found that owing to the strong dependence of wave height on wind speed, for resolution coarser than 70 km the loss of accuracy of the wind fields, even if meteorologically acceptable, makes them useless for an efficient evaluation of the wave conditions. The exception, explained by the local absence of relevant mountain ridges, is the case of a southerly wind in the eastern Mediterranean. The accuracy of wave forecasting is obtained by comparing analysis and forecast fields for a very severe storm. In connection with the preferential west to east flow of most of the Mediterranean storms, and with the scarcity of information on the Atlantic Ocean, the equality of the meteorological forecast rapidly deteriorates beyond 1 or 2 days of forecast. This leads to an even faster deterioration of the wave forecast, whose practical limits in the western Mediterranean can at present be established at 1 day.

Journal of Geophysical Research, 1991

We describe the procedure followed and the data used for the preparation of an atlas of the wind and wave conditions in the Mediterranean Sea. The two basic sources of data have been the altimeters on board of the ERS-1/2 and TOPEX/Poseidon satellites and the operational wind and wave results of the European Centre for Medium-Range Weather Forecasts. The data have been combined providing a ten year data-set from which both overall and point by point statistics have been derived. The results are critically analysed and suggest an underestimate of the altimeter derived wind speeds in the Mediterranean Sea.

2021

The global coverage of the observational network of the wind waves is still characterized by the significant gaps in in situ observations. At the same time wind waves play an important role into the Earth' climate system specifically in the air-sea interaction processes and energy exchange between the ocean and the atmosphere. In this paper we present the SeaVision system for measuring wind waves' parameters in the open ocean with navigational marine X-band radar and prime data collection from the three research cruises in the North Atlantic (2020 and 2021) and Arctic (2021). Simultaneously with SeaVision observations of the wind waves we were collecting data in the same locations and time with Spotter wave buoy and running WaveWatch III model over our domains. Measurements with SeaVision were quality controlled and validated by comparison with Spotter buoy data and WaveWatch III experiments. Observations of the wind waves with navigational Xband radar are in agreement among these three sources of data, with the best agreement for wave propagation directions. The dataset that supports this paper consists of significant wave height, wave period and wave energy frequency spectrum from both SeaVision and Spotter buoy. Currently the dataset is available through the temporary link (https://sail.ocean.ru/tilinina2021/) while supporting dataset (Tilinina et al., 2021) is in technical processing at PANGAEA repository. The dataset can be used for validation of satellite missions as well as model outputs. One of the major highlights in this study is potential of all ships navigating into the open ocean and equipped with X-band marine radar to participate into the development of another observational network for the wind waves in the open ocean once cheap and independently operating version of the SeaVision (or any other system) is available.

Aquatic Ecosystem Health & Management, 2020

Between the evening of October 23rd and the evening of October 24th 2017, a sea storm hit the city of Bari, along the Adriatic coast, in the south of Italy, causing widespread damages. Due to the absence of direct observations of wave characteristics, the present paper is aimed to (i) compare the development of the occurred sea storm as hindcasted by ’84 method with the predictions by atmosphere-ocean numerical models and satellite observations and (ii) estimate the most reliable value of the significant wave height, Hs, at the peak of the sea storm, with its associated return period. As a result, the ’84 showed the better agreement with the satellite observations in determining the value of Hs at the peak of the sea storm, compared with the predictions by more sophisticated atmosphere-ocean numerical models. In particular, the obtained value of Hs, equal to 6.58 m, makes the investigated sea storm an exceptional event.

Ocean Engineering, 2007

We have hindcast the wind and wave conditions in the Mediterranean Sea for two 1-month periods. Four different meteorological models and three different wave models have been used. The results have been compared with satellite and buoy wind and wave observations. Several conclusions concerning both the instruments and the models have been derived. The quality of both wind and wave results has been assessed. Close to the coasts high resolution, nested wave models are required for sufficient reliability.

Natural Hazards and Earth System Science, 2008

On 14 February 2005 a severe mistral storm caused substantial damage to the passenger cruiser "Voyager" between Balearic Islands and Sardinia. The storm had been well predicted. However, the ship was hit by one or more, apparently unexpected, large waves. Our aim was to understand if this was a freak event or it was within the expectable probability. At this aim we use our best estimate of the local wave conditions, obtained combining modelling and measured data. Starting from these we derive the probability of large waves, considering both linear and non-linear cases. Notwithstanding a correction towards the worse of the, otherwise inconsistent, available reports, on the basis of the data at disposal we conclude that, given the local conditions, the event was within the range of the potentially expectable wave heights. This turns out to be even more the case on the basis of recent results based on theoretical and experimental data.

2012

1] The coastal areas of the North-Western Mediterranean Sea are one of the most challenging places for ocean forecasting. This region is exposed to severe storms events that are of short duration. During these events, significant air-sea interactions, strong winds and large sea-state can have catastrophic consequences in the coastal areas. To investigate these air-sea interactions and the oceanic response to such events, we implemented the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System simulating a severe storm in the Mediterranean Sea that occurred in May 2010. During this event, wind speed reached up to 25 m.s À1 inducing significant sea surface cooling (up to 2 C) over the Gulf of Lion (GoL) and along the storm track, and generating surface waves with a significant height of 6 m. It is shown that the event, associated with a cyclogenesis between the Balearic Islands and the GoL, is relatively well reproduced by the coupled system. A surface heat budget analysis showed that ocean vertical mixing was a major contributor to the cooling tendency along the storm track and in the GoL where turbulent heat fluxes also played an important role. Sensitivity experiments on the ocean-atmosphere coupling suggested that the coupled system is sensitive to the momentum flux parameterization as well as air-sea and air-wave coupling. Comparisons with available atmospheric and oceanic observations showed that the use of the fully coupled system provides the most skillful simulation, illustrating the benefit of using a fully coupled ocean-atmosphere-wave model for the assessment of these storm events.

TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation