The main task of this project, “108-109 UV-Index Monitoring Analysis and Instrument Calibration Laboratory” is to enhance the UV monitoring ability in Taiwan. The objective of this project are : (1) To maintain the correctness of the UV monitoring values. (2) To provide the information on UV monitoring and analysis. (3) To execute UV instruments calibration quality control. Beside of operational works, the following jobs have been done:
The data of the UV monitoring system is analyzed. It is shown that the ratio of valid data is quite high. The variation of the observation is stable. The proportion of the radiation sustained during noon in daily total amount appears high in winter and low in summer. The probability of UVI monthly mean and larger than hazard-scale (UVI≧11) show spatial and inter-annual variability. Climate and weather as well as UVI changed abruptly. From January to April, September to October of 2019 and from June to August of 2020 and May, September of 2021, Taiwan’s UVI showed higher than in the past. Furthermore, meteorological data such as maximum temperature, diurnal temperature range, vapor pressure, cloudiness, and precipitation have been analyzed to explore the causes of monthly UVI anomalies.
To maintain the correctness of UV monitoring values, UVI Calibration Lab. did the calibration of 40 UV radiometers in 2019 to 2021. (12 new Solar Light 501A UVB instruments were added in 2019 to 2021).
In 2019 to 2021, UVI Calibration Lab. not only completed the calibration of 83 radiometers of CWB (including new instruments, spare parts and instruments on the CWB’s weather monitoring station) but also to provide UV instrument operation training.
All works proposed have been accomplished. The content of the raw data and statistics analyzing result of observations, and UV instrument calibration records have been kept and updated by schedule. All these work are useful for understanding the changing trend of the UV index in Taiwan and maintaining the correctness of the UV monitoring values.