Numerical Modelling of Sea Storms Occurred over the Black Sea

The objective of this study is to use numerical wave models to predict the extreme storm conditions in the Black Sea. In the past and recent years, two historical storms (February 1979 and February 6-8, 2012) that caused significant damages along the Bulgarian coast and a historical storm (February 2003) affecting the eastern part of the Black Sea and two storms (February 1999 and March 2013) that impacted southern coast of the Black Sea occurred in the Black Sea. In this study, simulations are conducted for these past and recent storms that strongly affected the coasts of the Black Sea. For the prediction of waves occurred during these storms, the third-generation numerical wave hindcast model SWAN has been applied. The ERA-Interim and CFSR winds are used as inputs to the SWAN model for modelling of the storms. The validation of the results is made by performing comparisons against in situ measurements from two buoys (data for 1999 at Hopa and 2003 at Gelendzhik) during two storms. In addition, spatial and temporal developments of the storms are examined. According to the results obtained it is seen that SWAN model using the CFSR wind fields performed better than SWAN model with ERA Interim winds and, among the used combinations, it is determined that the combination including Komen formulation for wind growth and Janssen formulation for whitecapping with whitecapping coefficient (Cds) equaling to 1.5 (Komen & Janssen Cds= 1.5) is the best.

Karadeniz’de Meydana Gelmiş Deniz Fırtınalarının Sayısal Modellenmesi

Bu çalışmanın hedefi, Karadeniz’de ekstrem dalga şartlarını tahmin edebilmek için sayısal dalga tahmin modellerini kullanmaktır. Geçmişte, Bulgaristan kıyıları boyunca belirgin hasarlara neden olan iki tarihsel fırtına (Şubat 1979 ve Şubat 6-8, 2012), Karadeniz’in doğu bölgesini etkileyen tarihsel bir fırtına (Şubat 2003) ve Karadeniz’in güney kıyılarını etkileyen iki fırtına (Şubat 1999 ve Mart 2013) meydana gelmiştir. Bu çalışmada, Karadeniz’in kıyılarını güçlü bir şekilde etkilemiş bu fırtınaların sayısal modellenmesi için analizler yürütülmüştür. Üçüncü nesil sayısal dalga tahmin modeli SWAN, bu fırtınalar boyunca meydana gelmiş dalgaların tahmini için Karadeniz’e uygulanmıştır. ERA-Interim ve CFSR rüzgar alanları fırtınaların modellenmesinde SWAN modele girdi olarak tanımlanmıştır. Sonuçların doğrulaması, iki fırtına boyunca iki ölçüm istasyonundan (Hopa istasyonunda 1999 yılına ait ve Gelendzhik istasyonunda 2003 yılına ait ölçüm verileri) temin edilmiş dalga ölçümleri ile karşılaştırılarak yapılmıştır. Bunlara ilave olarak, fırtınaların alansal ve zamansal gelişimleri incelenmiştir. Elde edilen sonuçlara göre; CFSR rüzgar alanlarını kullanan SWAN modelinin, ERA Interim rüzgar alanlarını kullanan modele göre daha iyi olduğu ve geliştirilmiş kombinasyonlar arasında rüzgar artışı olarak Komen formülünü ve köpüklenme için köpüklenme katsayısı (Cds) 1,5 olarak ayarlanmış Janssen formülünü içeren kombinasyonun (Komen & Janssen Cds= 1.5) en iyi sonuçlara sahip olduğu belirlenmiştir.

Kaynakça

Akpınar, A., Bingölbali, B., Van Vledder, GPh. 2016. Wind and wave characteristics in the Black Sea based on the SWAN model forcing with the CFSR winds. Ocean Eng., (submitted to Journal for publication).

Akpınar, A., Bekiroglu, S., Van Vledder, GPh., Bingölbali, B. 2015. Temporal and Spatial Analysis of Wave Energy Potential Along the Southern west Coasts of the Black Sea. Project Number: 214M436, TUBITAK Project (In Progress).

Akpınar, A., Van Vledder, GPh., Kömürcü, M.I., Özger, M. 2012. Evaluation of the numerical wave model (SWAN) for wave simulation in the Black Sea. Cont. Shelf Res., 50-51: 80- 99.

Anfuso, G., Rangel-Buitrago, N., Cortés-Useche, C., Iglesias Castillo, B., Gracia, F.J. 2015. Characterization of storm events along the Gulf of Cadiz (eastern central Atlantic Ocean). Int. J. Climatol., in press.

Behrens, A., Günther, H. 2009. Operational wave prediction of extreme storms in Northern Europe. Nat. Hazards, 49: 387– 399.

Belberov, Z., Trifonova, E., Valchev, N., Andreeva, N., Eftimova, P. 2009. Contemporary reconstruction of the historical storm of February 1979 and assessment of its impact on the coastal zone infrastructure. Proceedings of International Multidisciplinary Scientific GeoConference - SGEM’2009, 2, 243-250.

Galabov, V., Kortcheva, A., Bogatchev, A., Tsenova, B. 2015. Investigation Of The Hydro-Meteorological Hazards Along The Bulgarian Coast Of The Black Sea By Reconstructions Of Historical Storms. J. Environ. Prot. Ecol., 16 (3): 1005-1015.

Galabov, V., Kortcheva, A. 2013. The influence of the meteorological forcing data on the reconstructions of historical storms in the Black Sea. Proceedings of 13th International Multidisciplinary Scientific GeoConference - SGEM 2013.

GEBCO. 2014. British Oceanographic Data Centre, Centenary Edition of the GEBCO Digital Atlas [CD-ROM]. Published on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization, Liverpool.

Günther, H., Hasselmann, S., Janssen, P.A.E.M. 1992. The WAM model Cycle 4 (revised version), Deutsch. Klim. Rechenzentrum, Rep. No. 4, Hamburg, Germany.

Hasselmann, K. 1974. On the spectral dissipation of ocean waves due to whitecapping, Bound.-layer Meteor., 6(1): 107-127.

Janssen, PAEM. 1991a. Quasi-linear theory of wind-wave generation applied to wave forecasting. J. Physical Oceanogr., 21: 1631-1642.

Janssen, PAEM. 1991b. Consequences of the effect of surface gravity waves on the mean air flow. Int. Union of Theor. And Appl. Mech. (IUTAM), Sydney, Australia, 193-198.

Naga Kumar, K.Ch.V., Hema Malini, B., Nageswara Rao, K., Demudu, G., Aggrawal, R., Ramachandran R., Rajawat, A.S. 2015. Occurrence Of Storms And Storm Surges Along East Coast Of India. The Deccan Geographer, 53 (2): 12-25.

Özhan, E., Abdalla, S. 1998. Wind-wave climate of the Black Sea and the Turkish coast (NATO TU-WAVES project). Proc. 5th Int. Workshop on Wave Hindcasting and Forecasting, Jan. 27- 30, Melbourne, Florida, USA, pp. 71-82.

Pierson, WJ., Moskowitz, L. 1964. A proposed spectral form for fully developed wind seas based on the similarity theory of S.A. Kitaigorodskii, J. Geophysical Res., 69 (24): 5181-5190.

Ponce de Leon, S., Guedes Soares, C. 2015. Hindcast of the Hercules winter storm in the North Atlantic. Nat. Hazards, 78: 1883-1897.

Rusu, L., Ponce de Leon, S., Guedes Soares, C. 2015. Numerical modelling of the North Atlantic storms affecting the West Iberian coast. Maritime Technology and Engineering – Guedes Soares & Santos (Eds) Taylor & Francis Group, London, ISBN 978-1-138-02727-5.

WAMDI group. 1988. The WAM model – a third generation ocean wave prediction model, J. Phys. Oceanogr., 18: 1775-1810.

Yüksek, Ö., Karasu, S., Kömürcü, Mİ. 2000. Analysis of a severe storm and its damages. Proceedings of National Costal Engineering Symposium, Çanakkale, Turkey

Kaynak Göster