PARI has been processing and analyzing ocean wave data acquired by the Nationwide Ocean Wave information network for Ports and HArbourS (NOWPHAS) since 1970. With increasing concern about climate change, we must continue this analysis and provide wave information that is relevant for practical port and coastal works.

Therefore, in this study, we make out quick and definite information based on data observed at each station on NOWPHAS. We also conduct statistical analyses, compile annual reports on NOWPHAS and accumulate tide level and wind data. In addition, we conduct on-site observation using highly accurate capacitive wave gauges, establish a method to estimate 2-D higher wave number spectra, and develop a method to estimate ocean winds and waves using synthetic-aperture radar including TerraSAR-X.

In FY 2017, we conducted statistical analyses of ocean wave data obtained in 2016 and compiled the annual report on NOWPHAS. It included the local highest significant wave heights at 14 stations, consisting of 7 stations having seabed wave gauge (e.g. Kushiro and Mutsuogawara) and 7 stations having GPS-mounted wave buoys (e.g. East Aomori). Especially, the high waves caused by Typhoon Lionrock in 2016, which made landfall in the Tohoku region for the first time since 1951 when the Japan Meteorological Agency started to take typhoon statistics, were observed at many stations.

Also, we extracted the tsunami waves caused by Off-Fukushima Earthquake on November 22, 2016 and confirmed that the tsunami arrived at the Pacific coast of the Tohoku region. Especially, the tsunami height was slightly less than 20 cm and approximately 70 cm at the GPS-mounted wave buoy off the Fukushima coast and the tide station in Sendai-Shiogama Port, respectively.

In addition, we improved the accuracy of the tsunami profile on a GPS-mounted wave buoy by an appropriate preprocess of the sea surface elevation data.

Continuously, we intend to compile annual reports on NOWPHAS, to analyze noticeable tsunami and ocean wave events, and to improve wave data processing and analysis methods. We also intend to use the results of our work to design port and coastal facilities and to prevent disasters.