Assessment of meteorological climate models as inputs for coastal studies

Abstract

Modeling studies of future changes in coastal hydrodynamics, in terms of storm surges and wave climate, need appropriate wind and atmospheric forcings, a necessary requirement for the realistic reproduction of the statistics and the resolution of small scale features. This work compares meteorological results from different climate models in the Mediterranean area, with a focus on the Adriatic Sea, in order to assess their capability to reproduce coastal meteorological features and their possibility to be used as forcings for hydrodynamic simulations. Five meteorological datasets are considered. They are obtained from two regional climate models, implemented with different spatial resolutions and setups and are downscaled from two different global climate models. Wind and atmospheric pressure fields are compared with measurements at four stations along the Italian Adriatic coast. The analysis is carried out both on simulations of the control period 1960-1990 and on the A1B Intergovernmental Panel for Climate Change scenario projections (2070-2100), highlighting the ability of each model in reproducing the statistical coastal meteorological behavior and possible changes. The importance of simulated global-and regional-scale meteorological processes, in terms of correct spatial resolution of the phenomena, is also discussed. Within the Adriatic Sea, the meteorological climate is influenced by the local orography that controls the strengthening of north-eastern katabatic winds like Bora. Results show indeed that the increase in spatial resolution provides a more realistic wind forcing for the hydrodynamic simulations. Moreover, the chosen setup and the global climate models that drive the regional downscalings appear to play an important role in reproducing correct atmospheric pressure fields. The comparison between scenario and control simulations shows a small increase in the mean atmospheric pressure values, while a decrease in mean wind speed and in extreme wind events is observed, particularly for the datasets with higher spatial resolution. Finally, results suggest that an ensemble of downscaled climate models is likely to provide the most suitable climatic forcings (wind and atmospheric pressure fields) for coastal hydrodynamic modeling. 556 Ocean Dynamics (2012) 62:555-568

Wave climate of the Adriatic Sea: a future scenario simulation

“…The adopted COSMO-CLM wind products were analyzed and assessed in the work of Bellafiore et al (2012), where wind fields resulting from different regional climate models were compared versus observations collected at four different wind stations in the Adriatic Sea area. The results presented showed that C14E5 dataset was the best performing among five different datasets in reproducing the mean and extreme wind conditions in the Adriatic Sea, even if the tendency to underestimate Bora winds was shown.…”

Knowledge discovery in large model datasets in the marine environment: the THREDDS Data Server example

“…In addition, climate change induced effects at global or regional scales have not been yet completely understood, and as a consequence there is a large uncertainty on the effects that they may have on coastal zones [2].…”

An operational forecasting system for the meteorological and marine conditions in Mediterranean regional and coastal areas

“…This is an indication that the problem is in the correct prediction of the bora-easterly winds. This problem has been recently discussed from the meteorological point of view in Bellafiore et al (2012) for the northern Adriatic Sea. In view of the complex orography of the area, given that the operational BOLAM runs at 0.1…”

“…The two main problems with surface wind forecast are the parametrisation of the boundary layer processes and the spatial resolution of the meteorological model. There are many studies in literature (for Mediterranean Sea see, e.g., Signell et al, 2005;Bertotti et al, 2006Bertotti et al, , 2009Cavaleri and Bertotti, 2003;Cavaleri and Sclavo, 2006;Bellafiore et al, 2012) indicating that the use of meteorological hydrostatic limited area models (LAM) can effectively improve wave forecast at regional scale, in particular where the the topography affects significantly the mesoscale flow.…”