Browsing by Author "Soran, Mehmet Burak"

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Quality of the ERA5 and CFS winds and their contribution to wave modelling performance in a semi-closed sea
(Taylor & Francis, 2021-03-12) Çalışır, Emre; Soran, Mehmet Burak; Akpınar, Adem; Çalışır, Emre; Soran, Mehmet Burak; AKPINAR, ADEM; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0002-5422-0119; AAC-6763-2019; JJU-1857-2023; GCE-1854-2022
This study aims to investigate the quality of ERA5, a recent reanalysis wind product, and its contribution to wave modelling performance in a semi-closed sea, the Black Sea. This investigation includes a comparison of ERA5 surface wind fields with the ones from the CFSR to assess if this latest reanalysis improved the representation of the surface winds. Wind speeds from both reanalyses were validated with measurements at Gloria, the only sea wind measurement station on the Black Sea. Validations were also conducted using altimeter and scatterometer satellite data after which results were later compared against each other. The second aim of this study investigates whether a wave hindcast model forced with the ERA5 wind fields has improved prediction of wave parameters. A SWAN model with default settings was used to compare the results under the same conditions. Performance analyzes of the default SWAN wave estimates with both ERA5 and CFSR winds were conducted using three offshore buoy measurements and altimeter data of satellites over the Black Sea. Results show that ERA5 winds are more biased compared to CFSR winds at Gloria location. Both CFSR and ERA5 underestimate wind speeds. ERA5 performs better than the CFSR in lower wind speeds and worse in higher wind speeds. However, ERA5 winds have less bias and are more scattered than the CFSR winds against the satellite data. SWAN driven by CFSR winds performs better than the one driven by ERA5 winds against both buoy and satellite data.
Spatial calibration of wavewatch iii model against satellite observations using different input and dissipation parameterizations in the black sea
(Pergamon-elsevier Science Ltd, 2022-06-01) Akpınar, Adem; AKPINAR, ADEM; Soran, Mehmet Burak; Amarouche, Khalid; AMAROUCHE, KHALID; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0001-7983-4611; 0000-0002-9042-6851; AFR-7886-2022; AAC-6763-2019
The quality of the third generation wave model WAVEWATCH III, referred WW3, using the different source term packages is investigated in the context of wave growth and dissipation in a semi-closed sea, Black Sea. Accuracy in wave height hindcast is tested for five different source term parameterizations ST1, ST2, ST3, ST4, and ST6 in WW3 against the 2020-year multi-mission satellite observations over the entire sea. The aims are to determine the most appropriate formulation and optimum tuneable coefficients for wind waves modelling in the Black Sea. For this purpose, significant wave heights (Hm0) are produced using five different source term packages implemented in the WW3 model. A sensitivity test was applied to define the tuneable parameters that contributes to the accuracy of the models, and subsequently the coefficient values of each parameters was turned to calibrate the WW3 models. The tuneable parameter allowing to obtain the most accurate result in each package are defined for each source term package. Comparing between model results and satellite observations, we found that the default WW3 model with all source terms as well as the calibrated ST2 model underestimate Hm0 in the entire domain and mainly in the eastern Black Sea region and are not suitable physical source term for the Black Sea. In the Black sea, the calibrated ST1, ST3 and ST4 forced with ERA5 wind are recommended for long term wave climate simulation, and the calibrated ST6 is recommended for extreme wave simulation.