EPA-99-L105-02-201

099

1,700 千元

2010/02/05

2010/12/31

吳明進

監資處

徐禾杰

國立台灣大學

環境資訊系統

紫外線指數、監測與預報、儀器校驗

UVI, Monitoring and forecasting, calibration

柳中明

譚俊傑

02-23655671#151

leehl@ncdr.nat.gov.tw

「99年度紫外線預報系統與儀器校驗實驗室」專案計畫 (以下簡稱本計畫) 以提高國內紫外線預報與監測之正確性為任務，年度專案計畫目標如下：一、發展紫外線指數數值動力預報模式系統；二、維護紫外線監測數值之正確性；三、提供紫外線預報輔助資訊；四、紫外線輻射計校驗品質管理。除了一般作業之外，完成下列工作: 第四代紫外線指數預報系統持續進行作業預報。第五代紫外線數值動力預報系統也於2010年10月中開始上線進行平行預報，隨著預報程式的改善及預報所需資料取得較為穩定後，預期預報成效逐步提升。第五代系統使用MM5模擬之雲量資料代入預報模式中，再利用修正公式加以校正，改善過去預報系統受到人為主觀資料的影響，有效增進預報準確度。 紫外線監測系統之觀測資料分析結果顯示:紫外線指數的監測資料有效率相當高，資料也漸趨平穩。各站過量級以上的出現機率在2008年內顯著增加，使得目前各站趨勢呈現為增加的正趨勢；午時輻射佔全日輻射量比例冬高夏低的特徵相當清楚；危險級與UVI≧8的出現機率具區域差異與逐年變化特徵。月與月間之天氣氣候變化快速，導致UV輻射也快速變化。此外本計畫應用最高溫、日較差、水汽壓、雲量及降水場等氣候參數分析，探討逐月UVI觀測異常的可能原因。 進行紫外線監測及預報成效分析。結果顯示: 紫外線指數的預測誤差上下變動幅度逐年相近。另外，分析天氣圖和測站氣溫和濕度以及衛星雲圖，探討預報誤差大的個案發生的可能原因以幫助改進UVI 預報。 本年度計畫依要求完成各項交付之工作內容。設置計畫網站呈現監測、預報分析以及儀器校驗相關圖集及數據；於每季提報上一季紫外線監測資料分析報告、儀器校驗狀態及預報分析成果報告、召開討論會議，均有利於瞭解紫外線指數的變化趨勢及預報與監測能力。

紫外線指數、監測與預報、儀器校驗

EPA-99-L105-02-201.pdf

11MB

2011/3/1 上午 12:00:00

The main task of this project, “UV Forecast System and Monitoring Instrument Calibration Lab.-Fiscal year 99” is to enhance the UV forecast and monitoring ability in Taiwan. The objective of this project are :(1)to develop UV Index forecast numerical dynamical model system. (2) To maintain the numerical fidelity of UV monitoring. (3) To provide UV forecast auxiliary information. (4) To execute UV instruments calibration quality control. Beside of operational works, the following jobs have been done: While the UVI operational forecast with the forecast model of 4th generation keeps on, a parallel UV forecast has been made with a UVI forecast numerical dynamical model system, the 5th generation UVI forecast model, since mid- October of 2010. The performance of this new system is getting improved step by step after data inflow problem solved. This new system is organized as a two tier forecast. The first tier forecast uses the cloudiness simulated with a regional model, MM5. The second tier adds the CWB weather forecast in. This forecast system can remove the bias from subjective forecast and be expected to improve UVI forecast. 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 probability of UVI larger than” over-scale” at the stations significantly increased in 2008. Therefore, a positive long-term trend appeared. The proportion of the radiation sustained during noon in daily total amount appears high in winter and low in summer. Probability of UVI larger than hazard –scale as well as UVI≧8 show spatial and inter-annual variability. Climate and weather as well as UVI changed abruptly. Furthermore, meteorological data such as maximum temperature, diurnal temperature range, humidity, cloudiness, and precipitation have been analyzed to explore the causes of monthly UVI anomalies. UV monitoring and forecast data have analyzed. It is shown that UVI forecast performance is quite stable. Furthermore, in order to improving UVI forecasting, meteorological data such as weather map, station temperature and humidity, as well as satellite image have been studied while forecast is fail. All works proposed have been accomplished. A web site of UV monitoring and forecast has been maintained, the content of the raw data and statistics analyzing result of observations, and UV instrument calibration records have been kept and updated by schedule; held scheduled discussion meetings. All these work helps to enhance the UV forecast and monitoring ability in Taiwan.

UVI, Monitoring and forecasting, calibration