The Logistic Requirements for Wave Field Measurement Prof. Dr.-Ing. Chia Chuen Kao Director, Coastal Ocean Monitoring Center, National Cheng Kung University Dr. Laurence Zsu-Hsin Chuang Deputy Director, Coastal Ocean Monitoring Center, National Cheng Kung University Dr. Beng-Chun Lee Director, Marine Meteorology Center, Central Weather Bureau

Coastal Ocean Monitoring Center / NCKU Purposes of Wave Observation for the calibration and validation of wave models for the determination of local wave climate for the scientific research of marine phenomena provide "real time" data for the port operations, engineering constructions and disaster prevention, etc. provide “Ground Truth” for the calibration of satellite data

Coastal Ocean Monitoring Center / NCKU Wave Measurements in the Field In-situ methods –pressure sensor –resistance gauge –two-axis current meter –acoustic gauge –data buoy Remote sensing techniques –nautical radar –altimeter –Synthetic Aperture Radar (SAR) –scatterometer provide an extensive set of ocean surface data and will be the trend of wave measurement in the future.

Coastal Ocean Monitoring Center / NCKU The selection of tools depends on the –Purposes real-time / archives data –Budget affordability –Observation duration research / operational –Environment adjustability water depth / wave / wind / current

Coastal Ocean Monitoring Center / NCKU In-Situ Methods

Coastal Ocean Monitoring Center / NCKU Operational Ocean Monitoring System Coastal Hydrological Monitoring Network around Taiwan includes –pile stations –data buoys –tidal stations –coastal meteorological stations The systems applied to the Network are fully designed, developed, and constructed by COMC. Data Buoy is the main equipment for offshore measurement

Coastal Ocean Monitoring Center / NCKU Data Transmission System Data are transmitted real-time by : — UHF radio telemetry — Satellite telecommunication

Coastal Ocean Monitoring Center / NCKU Data Quality Control (QC) System " It is more risky to utilize erroneous data than none". COMC data QC system consists of automatic and manual procedures, –automated data quality methods according to NDBC/NOAA criteria are adopted and revised their local validity. –Experienced data analysts are responsible for the manual check of data quality. The Data Quality Control System has been developing, modifying, and operating as a routine work at COMC for some years.

Coastal Ocean Monitoring Center / NCKU Maintenance System Experienced team is essential to carry out the maintenance works. Maintenance and inspection are necessary in regular base due to harsh marine environment. –In-site inspection – every three months –Buoy retrieval for buoy hull refurbishment and sensor calibration – each year Quick response to system malfunction to guarantee the minimum data loss. –Permitted recover time shore station - 1 week offshore station - 2 weeks (depends on sea state)

Coastal Ocean Monitoring Center / NCKU Oceanographic Database System COMC database includes : –wind –wave –barometric pressure –air and water temperature –tide COMC offers archives data as well as real-time data COMC is willing to provide technical support for the international data exchange and associated services providing the mutual agreement between countries has been achieved

Coastal Ocean Monitoring Center / NCKU Concluding Remarks To provide long-term and high-quality data, an in-situ operational ocean monitoring system should adequately integrate –structures –mooring –sensors –data acquisition and control –data processing and analysis –data transmission –power –auxiliary sub-systems The most important logistic requirement for wave measurement is an experienced and disciplinary team COMC is willing to offer technical services for meteorological and oceanographic measurement in the Far East region

Coastal Ocean Monitoring Center / NCKU Data Buoy and Pile Station Measuring items – Wave – Wind – Barometric pressure – Air temperature – Water temperature – Tide – Current – Water quality (if needed) For long-term operational measurement - data buoy, pile station

Coastal Ocean Monitoring Center / NCKU Location of Data Buoys (by 2003) South China Sea (Spratly Is.) Vietnam Malaysia

Coastal Ocean Monitoring Center / NCKU Sketch of COMC Data Buoy COMC buoy has proven its reliability and survival ability in the harsh environment especially in typhoons.

Coastal Ocean Monitoring Center / NCKU Significant Wave Height During Typhoon AMBER

Coastal Ocean Monitoring Center / NCKU Data Flow of Monitoring System

Coastal Ocean Monitoring Center / NCKU Nan-Sha Wave Observation Location (10 o 21’00” N,14 o 22’05” E) at the offshore area of the T'ai- P'ing Tao (Itu-Aba Island ) in the NAN-SHA CH'ÜN-TAO (Spratly Islands), South China Sea Deployed in April 1999 Operated by COMC Data transmission through Inmarsat

Coastal Ocean Monitoring Center / NCKU Significant wave height Observed by Nan-Sha Buoy