Long-term Variations of Wind, Wave and Surge in Offshore China

Abstract

Hu, Y. and Li, J.; 2020. Long-term variations of wind, wave and surge in offshore China. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1438-1442. Coconut Creek (Florida), ISSN 0749-0208.Affected by the climate change, the meteorological and ocean elements in the world are experiencing a long-term variation. This study analyzes the long-term trends of wind, wave and surge in offshore China. The long-term data for trend analysis of wind speed (V), significant wave height (H) and surge (S) are obtained from a 35-year numerical simulation (1979-2013) which is driven by the blended wind data of reanalysis and typhoon model. The domain averaged V and H are analyzed. The results indicate that V and H increased from 1998 to 2013 while kept stable from 1979 to 1997 in general. The linear trend of V, H and S at every grid in the study area are studied by analysis of regression. It is found that V in the southeast part of China seas increases about 2cm/s per year. However, no obvious trend is showed for V in other locations of the study area. The long-term variations of H generally have similar distribution pattern as V which increases about 0.15cm per year in the southeast area. To understand the temporal variations of extremely big values of V, H and S, the maximum values of those elements are examined and found to be closely related to typhoon events in the northwest Pacific Ocean. The results of this study can be helpful for the exploitation of wind and wave resources or the planning of offshore constructions under the changing climate