Browsing by Author "Semedo, Alvaro"

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On the assessment of the wave modeling uncertainty in wave climate projections
(Iop Publishing Ltd, 2023-12-01) Lobeto, Hector; Semedo, Alvaro; Menendez, Melisa; Lemos, Gil; Kumar, Rajesh; Akpınar, Adem; Dobrynin, Mikhail; Kamranzad, Bahareh; AKPINAR, ADEM; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0002-9042-6851 ; AAC-6763-2019
This study investigates the epistemic uncertainty associated with the wave propagation modeling in wave climate projections. A single-forcing, single-scenario, seven-member global wave climate projection ensemble is used, developed using three wave models with a consistent numerical domain. The uncertainty is assessed through projected changes in wave height, wave period, and wave direction. The relative importance of the wave model used and its internal parameterization are examined. The former is the dominant source of uncertainty in approximately two-thirds of the global ocean. The study reveals divergences in projected changes from runs of different models and runs of the same model with different parameterizations over 75% of the ensemble mean change in several ocean regions. Projected changes in the wave period shows the most significant uncertainties, particularly in the Pacific Ocean basin, while the wave height shows the least. Over 30% of global coastlines exhibit significant uncertainties in at least two out of the three wave climate variables analyzed. The coasts of western North America, the Maritime Continent and the Arabian Sea show the most significant wave modeling uncertainties.
Regional wave climate projections forced by EURO-CORDEX winds for the Black Sea and Sea of Azov towards the end of the 21st century
(Wiley, 2023-07-21) Çakmak, Recep Emre; Çalışır, Emre; Lemos, Gil; Akpınar, Adem; Semedo, Alvaro; Cardoso, Rita M.; Soares, Pedro M. M.; ÇAKMAK, RECEP EMRE; Çalışır, Emre; AKPINAR, ADEM; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0002-9042-6851; KGQ-6522-2024; JJU-1857-2023; AAC-6763-2019
Wave phenomena impact high commercial value coastal and offshore activities, infrastructures and transportation. The knowledge of future wave conditions allows for consistent long-term planning and decision-making. The present study aims to provide robust, reliable projections of the potential future wave conditions of the Black Sea under the influence of climate change. For this purpose, an eight-member dynamic wave climate ensemble that accurately represents the Black Sea's present wave climate has been produced, and future projections are assessed and analysed here. The wave climate ensemble was obtained by forcing the Simulating Waves Nearshore spectral wave model with eight regional wind fields from the EURO-CORDEX. The future simulations of the regional wind fields are based on the RCP8.5 high-emission scenario. The historical wave climate of the ensemble was evaluated against ERA5 reanalysis data. Projected changes in the mean wind and wave characteristics are examined by comparing historical and future simulations. In addition, the projected trends in the annual means during the future period of the wave simulations for significant wave height (H-s) and wave energy flux are also analysed. The projections for H-s and wind speeds are pronounced with significant decreases down to -10% across the basin, especially in the eastern region of the Black Sea. Changes in the H-s 99% percentiles of up to 16% are projected to occur. The projected changes in the annual mean of the wave energy flux are close to the projected changes in H-s means, while the seasonal changes (between -15% and 12%) are expected to be higher.
Wave storm events in the western mediterranean sea over four decades
(Elsevier, 2022-01-14) Amarouche, Khalid; Akpınar, Adem; Semedo, Alvaro; AMAROUCHE, KHALID; AKPINAR, ADEM; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü; 0000-0001-7983-4611; AAC-6763-2019; AFR-7886-2022
The rising intensity and recurrence of wave storm events can seriously impact navigation and coastal and offshore structures in the Western Mediterranean Sea. Therefore, the present study is focused on wave storm events in the Western Mediterranean Sea, over the last four decades. The spatial decadal variations of wave storm events are shown, considering variations in the parameters that characterise wave storms, such as significant wave height (SWH), wave storm duration, and wave storm direction. Additionally, the decadal variation in wave storm intensities is evaluated through the storm power index (SPI) and the total storm wave energy (TSWE). The study is based on a wave hindcast, developed using a calibrated SWAN model. The wave storm events are obtained based on the SWH time series for 24 325 locations, distributed over an unstructured grid, covering the entire Western Mediterranean Sea. The decadal variation in the number of wave storm events, maximum and mean wave storm duration, SPI, and TSWE were observed in large parts of the West Mediterranean Sea during the last four decades. However, variations in mean SWH during these storms are low, and do not show a real implication in the decadal changes in the wave storm intensity (SPI and TSWE). Locations of significant increasing changes in SPI and TSWE show a dependence on changes in the wave storm duration. They may be related to variations in wave storm direction in some areas. Increases in wave storm duration are mainly responsible for increases in wave storm intensities over the last decade.