Analysis of the Coastal Mixing Processes and Long-Term Monitoring of Coastal Environment of Western Coast of Taiwan

The aims of present study are twofold, first to provide the long-term monitored data as the coastal environment baseline at the western coast of Taiwan and second, study the coastal mixing processes using the latest technologies. In present project, a coastal monitoring station had been set up near the Taoyuan algal reef and served as a test platform, from which the continuous time series of the air-sea CO2 flux, sea water quality data and nearshore hydrodynamic data have been recorded since 2010. In this year, the coastal monitoring station will be operated, maintained and expanded, in terms of observation item, under the support from this project. A state-of-the-art HF coastal radar system that consisted of 32 antennas array will be installed in the station for the mapping of wave field, current field and wind field of the northern Taiwan Strait. For the high frequency radar: two HF-radar systems with 32 antennas and 16 antennas arrays each, that developed by University of Hawaii, will be set up at the NCU coastal observatory. The radar systems, which are provided by Prof. Pierre Flament at University of Hawaii under the collaboration agreement with National Central University, are working at 24MHz. This radar system features the finest azimuthal resolution worldwide that especially designed for wave field mapping. It is planned to install the radars in 2018. In present study, a simulation test bed (End-to-End-Simulation, E2ES) for HF radar will be setup to validate and test the algorithms for wave parameters including wave height, period, propagate direction and directional spreading and also the directional wave spectrum. The E2ES will be setup based on the theories of second-order radar echo proposed by Barrick (1972) and Gill et al. (2006). Doppler-Range spectra will be simulated for monsoon and typhoon conditions as the given target. Algorithms and estimators that proposed by Barrick(1977), Marresca (1997), Graber et. al (2000) and Grugel et. al.(2006) will be implemented and tested and tuned. Concerning the tuning, the coupling coefficient in the theory for the EM wave and surface gravity waves will be discussed from both theoretical foundation and experimental data.For the coastal mixing in the inner shelf, which is the dominating processes in the land-ocean interactions, will be discussed using observational data. The self-developed miniaturized surface drifters array will be deployed in the field campaigns in the vicinity waters around the Taoyuan algal reef. These surface current maps and their temporal evolution will be used for quantitatively assess the mixing efficiency under various turbulence and stratification conditions.