Rip currents in the non-tidal surf zone with sandbars : numerical analysis versus field measurements

• Autorzy: Dudkowska Aleksandra , Boruń Aleksandra , Malicki Jakub , Schönhofer Jan , Gic-Grusza Gabriela

Identyfikatory

DOI

10.1016/j.oceano.2020.02.001

• Języki publikacji: EN

Abstrakty

EN

Rip currents, which are local seaward-directed jets with their mean velocity exceeding 0.5 m/s, have been a subject of many studies since the 1940s. They are an important part of the nearshore current system and in specific hydro- and litomorphological conditions can cause changes in the local bathymetry. Thus, a detailed analysis of the characteristics of this phenomenon is crucial both to public safety and hydroengineering. The main purpose of this research is to determine the wave conditions of a multi-bar non-tidal coastal zone environment in which rip currents can occur. In this study, we focus on a multi-bar non-tidal coastal zone environment located in the Southern Baltic Sea, where rip current driving forces are mostly reduced to the wind and wind-induced waves. This is one of very few comprehensive approaches to exploring the possibility of rip currents occurrence in such environmental conditions. During two field expeditions, there were carried out in situ measurements exploiting two GPS drifters. The results indicate the formation of irregular non-longshore flows (related to rip currents) in the studied area. To answer the question under what conditions the formation of rip currents takes place, an extended modelling experiment was performed. Deep-water wave conditions typical of the studied area were chosen due to bouy measurements. The total of 589 combinations of the significant wave height, the mean period and wave direction values were examined as test cases. The coastal flow in the area and tracks of virtual drifters were simulated by XBeach numerical model for all test cases. As a result, 589 nearshore currents fields were generated and two scenarios were indicated: a regular circulation (dominated by the longshore current) which is typical of this area (547 cases), and flows with rip current features (42 cases). This reflects the results of the field measurements carried out. It can be concluded that the wave direction is a dominating factor in the formation of rip currents. Namely the flows of this type may occur in the area of interest when the direction of a deep water wave is almost perpendicular to the shore. Such situations occur rarely. They cover about 7% of the days of the year. Thus, rip currents do not appear to be a significant factor in the reconstruction of the sea bottom in the studied area.

Słowa kluczowe

EN

rip current; coastal zone; coastal flows; wind-wave conditions

• Wydawca: Polish Academy of Sciences, Institute of Oceanology ; Elsevier
• Czasopismo: Oceanologia
• Rocznik: 2020
• Tom: No. 62 (3)
• Strony: 291--308
• Opis fizyczny: Bibliogr. 30 poz., fot., rys., tab., wykr.

Twórcy

autor

Dudkowska Aleksandra

• University of Gdańsk, Institute of Oceanography, Gdynia, Poland

autor

Boruń Aleksandra

• University of Gdańsk, Institute of Oceanography, Gdynia, Poland

autor

Malicki Jakub

• Institute of Hydro-Engineering, Polish Academy of Sciences, Gdańsk, Poland

autor

Schönhofer Jan

• Institute of Hydro-Engineering, Polish Academy of Sciences, Gdańsk, Poland

autor

Gic-Grusza Gabriela

• University of Gdańsk, Institute of Oceanography, Gdynia, Poland

Bibliografia

• [1] Booij, N., Holthuijsen, L. H., Ris, R. C., 1996. The SWAN wave model for shallow water. In: Proceedings of the 25th International Conference on Coastal Engineering, Orlando, USA, 1, 668-676.
• [2] Bruneau, N., Bonneton, P., Castelle, B., Pedreros, R., 2011. Modeling rip current circulations and vorticity in a high-energy mesotidal-macrotidal environment. J. Geophys. Res. 116(C7), 17, C07026, https://doi.org/10.1029/2010JC006693.
• [3] Castelle, B., Almar, R., Dorel, M., Lefebvre, J.-P., Senechal, N., Anthony, E., Laibi, R., Chuchla, R., du Penhoat, Y., 2014. Rip currents and circulation on a high-energy low-tide-terraced Beach (Grand Popo, Benin, West Africa). J. Coastal. Res. 70, 633-638, https://doi.org/10.2112/SI70-107.1.
• [4] Castelle, B., Scott, T., Brander, R., McCarroll, R., 2016. Rip current types, circulation and hazard. Earth-Sci. Rev. 163, 1-21, https://doi.org/10.1016/2016.09.008.
• [5] Cieślikiewicz, W., Dudkowska, A., Gic-Grusza, G., Jędrasik, J., 2017. Extreme bottom velocities induced by wind wave and currents in the Gulf of Gdańsk. Ocean Dynam. 67(11), 1461-1480, https://doi.org/10.1007/s10236-017-1098-4.
• [6] Floc’h, F., Mabiala, G. R., Almar, R., Castelle, B., Hall, N., Du Penhoat, Y., Scott, T., Delacourt, C., 2018. Flash rip statistics from video images. J. Coastal. Res. 81, 100-106, https://doi.org/10.2112/SI81-013.1.
• [7] Furmańczyk, K., 1994. Strefa brzegowa Półwyspu Helskiego w świetle kompleksowej interpretacji zdjęć lotniczych i satelitarnych. Mar. Sci. 134(2), 61-80.
• [8] Furmańczyk, K., Andrzejewski, P., Benedyczak, R., Bugajny, N., Cieszyński, L., Dudzińska-Nowak, J., Giza, A., Paprotny, D., Terefenko, P., Zawiślak, T., 2014. Recording of selected effects and hazards caused by current and expected storm events in the Baltic Sea coastal zone. J. Coastal. Res. 70, 338-342, https://doi/org/10.2112/SI70-057.1.
• [9] Garnier, R., Calvete, D., Falqués, A., Dodd, N., 2008. Modelling the formation and the long-term behavior of rip channel systems from the deformation of a longshore bar. J. Geophys. Res. Oceans 113 (C7), art. no. C07053, 18 pp., https://doi.org/10.1029/2007JC004632.
• [10] Gic-Grusza, G., Dudkowska, A., 2014. Modeling of wind wave induced sediment transport in the coastal zone of polish marine areas (southern baltic). Baltic International Symposium (BALTIC), 2014 IEEE/OES: Measuring and modeling of multiscale interactions in the marine environment, May 26-29, 2014, Tallinn, Estonia IEEE/OES, 1-5, https://doi.org/10.1109/BALTIC.2014.6887860.
• [11] Grusza, G., 2007. Three-dimensional modelling of wave-generated currents in coastal zone. Ph.D. thesis, Inst. Oceanogr., Univ. Gdańsk, Gdynia, Poland, (in Polish).
• [12] Johnson, D., Pattiaratchi, C., 2004. Transient rip currents and nearshore circulation on a swell-dominated beach. J. Geophys. Res. Oceans 109, art. no. C020261, 20 pp., https://doi.org/10.1029/2003jc001798.
• [13] Johnson, D., Pattiaratchi, C., 2006. Boussinesq modelling of transient rip currents. Coast. Eng. 53, 419-439, https://doi.org/10.1016/j.coastaleng.2005.11.005.
• [14] Kirby, J., 2017. Recent advances in nearshore wave, circulation and sediment transport modeling. J. Mar. Res. 75(3), 263-300, https://doi.org/10.1357/002224017821836824.
• [15] Longuet-Higgins, M., Stewart, R., 1964. Radiation stresses in water waves; a physical discussion, with applications. Deep-Sea Res. Oceanogr. Abstr. 11 (4), 529-562, https://doi.org/10.1016/0011-7471(64)90001-4.
• [16] MacMahan, J., Thornton, E., Reniers, A., 2006. Rip current review. Coast. Eng. 53, 191-208, https://doi.org/10.1016/j.coastaleng.2005.10.009.
• [17] MacMahan, J. H., Thornton, E. B., Stanton, T. P., Reniers, A. J., 2005. RIPEX: observations of a rip current system. Mar. Geol. 218 (1), 113-134, https://doi.org/10.1016/j.margeo.2005.03.019.
• [18] Ostrowski, R., Schönhofer, J., Szmytkiewicz, P., 2016. South Balic representative coastal field surveys, including monitoring at the Coastal Research Station in Lubiatowo, Poland. J. Marine Syst. 162, 89-97, https://doi.org/10.1016/j.jmarsys.2015.10.006.
• [19] Peregrine, D., 1998. Surf zone currents. Theor. Comp. Fluid Dyn. 10, 295-309, https://doi.org/10.1007/s001620050065.
• [20] Pitman, S., Gallop, S. L., Haigh, I. D., Masselink, G., Ranasinghe, R., 2016. Wave breaking patterns control rip current flow regimes and surfzone retention. Mar. Geol. 382, 176-190, https://doi.org/10.1016/j.margeo.2016.10.016.
• [21] Pruszak, Z., Szmytkiewicz, P., Ostrowski, R., Skaja, M., Szmytkiewicz, M., 2008. Shallow-water wave energy dissipation in a multi-bar coastal zone. Oceanologia 50(1), 43-58.
• [22] Reda, A., Paplińska, B., 2002. Application of numerical wave model SWAN for wave spectrum transformation. Oceanol. St. 31(1-2), 5-21.
• [23] Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de Vries, J., Lescinski, J., McCall, R., 2010. XBeach Model Description and Manual. Rep. Unesco-IHE Institute for Water Education, Deltares and Delft University of Technology, Delft, Netherlands.
• [24] Rudowski, S., 1970. Smallscale ripples in offshore of the Southern Baltic Sea. Acta Geol. Pol. 20(3), 451-483.
• [25] Sabet, B. S., Barani, G., 2011. Field investigation of rip currents along the southern coast of the Caspian Sea. Sci. Iran. 18 (4), 878-884, https://doi.org/10.1016/j.scient.2011.07.017.
• [26] Schönhofer, J., 2014. Rip currents at beach with multiple bars theoretical description and in-situ observations. Ph.D. thesis, Inst. Hydro-Eng. PAN Gdańsk, Poland, (in Polish).
• [27] Sembiring, L., van Dongeren, A., Winter, G., Ormondt, M., Briere, C., Roelvink, D. J., 2014. Nearshore bathymetry from video and the application to rip current predictions for the Dutch Coast. J. Coastal. Res. 70, 354-359, https://doi.org/10.2112/SI70-060.1.
• [28] Short, A. D., Aagaard, T., 1993. Single and multi-bar beach change models. J. Coastal. Res. SI 15, 141-157.
• [29] Winter, G., van Dongeren, A., de Schipper, M., van Thiel de Vries, J., 2014. Rip currents under obliquely incident wind waves and tidal longshore currents. Coast. Eng. 89, 106-119, https://doi.org/10.1016/j.coastaleng.2014.04.001.
• [30] Xie, M., 2012. Three-dimensional numerical modelling of the wave-induced rip currents under irregular bathymetry. J. Hydrodyn. Ser. B. 24 (6), 864-872, https://doi.org/10.1016/S1001-6058(11) 60314-4.