109

2,419 千元

空氣品質監測

2020/04/30

2021/10/31

王聖翔

監資處

張志偉

國立中央大學

大氣空氣

微脈衝雷射雷達、氣膠垂直分布、國際合作

Micro pulse lidar (MPL), Aerosol vertical distribution, International collaboration

吳莆馨

03-4227151#65519

b95605041@g.ncu.edu.tw

空氣品質與氣象條件息息相關，從中小尺度環流至邊界層氣象的掌握，皆影響空氣品質預報與分析的成效。在過去的幾十年裡，東南亞各地區，有著高度的經濟與人口成長，大量增加的各類工廠、人為活動甚至生質燃燒等，便更進一步地降低此區域空氣品質。而台灣本土的空氣污染問題亦日益受到重視，中部至雲嘉南空品區經常性出現高PM2.5污染事件，類似之污染事件除了受排放源直接影響外，大氣擴散條件不佳亦為元凶之一，因此探討邊界層內的熱動力結構特性，將有助釐清污染成因。地面空氣品質監測網雖然能夠提供地面以及區域性的特性，但卻無法解釋垂直方向上氣膠分布的特性，因此利用光學遙測技術於長時間持續監測垂直方向氣膠光學特性，提供污染物在垂直剖面上隨時間演變的資料便顯得重要。 本計畫之目標與工作內容為(1)持續與NASA MPLNET進行國際合作交流，及技術諮詢與資料交換；(2)強化設備技術支援檢修量能與辦理教育訓練等工作以提升微脈衝雷射雷達系統觀測準確度；(3)協助提供微脈衝雷射雷達系統及太陽光度計之專業諮詢及相關儀器評估、監測站運轉之環境與安全資訊；(4)建構觀測資料庫並定期完成資料品質保證與品質管制作業；(5)整合微脈衝雷射雷達系統與環保署空氣品質測站等監測資料，提供高污染事件之可能成因分析報告，輔助空氣品質預報作業。 執行之重要成果如下： • 為提高資料品質並加強國際交流，本計畫持續與NASA MPLNET進行國際合作交流，包含技術諮詢與資料交換、調整與校準WFR設備，以強化微脈衝光達觀測量能。 • 為使亞洲指標站的運作更趨於正式及達臺美雙方合作的共識，今年度NASA MPLNET計畫主持人Dr. Welton也特地發函，正式指定EPA-NCU站為亞洲指標站。 • 為確保儀器運轉功能正常，夏季歲修期間於標準站房內將原有光達系統及三部新購入之儀器進行觀測平行比對、硬體檢測及清潔，並完成北中南三站持續運轉，與新增站點之運作順利。 • 提供環保署我國微脈衝雷射雷達監測網之短、中、長期之階段任務及對應的測站布設規劃，與專業技術諮詢及相關儀器評估、監測站運轉之環境與安全等資訊。 • 建立資料品質管控程序，特別針對儀器故障維修、供電異常等狀況，每月執行餘脈衝及觀測背景值之校正作業、並實施資料品保品管作業，確保資料可用率與穩定性；持續更新即時顯示網頁與觀測資料庫之維護。 • 以客觀統計方法定義出高污染並建立事件資料庫，將光達所觀測的氣膠垂直分布，整合地面空品與相關氣象資料，進行時間與空間上的多尺度分析，觀察污染物垂直及水平方向分布情形，釐清區域性污染傳送特徵，深入了解高污染事件之成因。

微脈衝雷射雷達、氣膠垂直分布、國際合作

2020成果報告.pdf

16MB

期末成果報告

2021/12/1 上午 12:00:00

The deterioration of air quality is strongly related to the meteorological condition. A better understating on the microscale, mesoscale, and PBL meteorology can effectively help the implement of air quality forecast and analysis. In the past decades, the Southeast Asia has experienced remarkable economic and population growth. The large increase in various types of factories, human activities, and biomass burning decreased the air quality over this region. The local air pollution of Taiwan gets more attention recently. High PM2.5 concentration events occur frequently in Central and Southern Taiwan, not only due to the emissions but also the weak atmospheric diffusion condition. Therefore, understanding the thermodynamics structure within PBL can help to clarify the cause of deteriorating air quality. Although the EPA Taiwan Air Quality Monitoring network provides the air quality information at the ground level, it cannot explain the PM2.5 characteristics in vertical. Therefore, observing the aerosol optical characteristics in the vertical direction by using remote sensing techniques, which can monitor the change of pollutants over time and space, is complementary for air quality monitoring. The objectives and task of this project are: (1) to continue the conduct of international collaborations cooperation with NASA MPLNET, and technical consultation and data exchange; (2) to strengthen the abilities to replace components that improve the accuracy of observation, also holding the training course for stations and equipment maintenance; (3) to offer professional consultation on micro-pulse lidar systems and sun photometers, evaluation of related equipment, and environmental safety information about the stations; (4) to build the lidar observation database and accomplish the operations of data QA/QC; (5) to integrate the observational data based on EPA MPL systems and air quality monitoring station, and further analyze the possible causes of high pollution events, also export its potential on air quality forecast. The important achievements from this project are listed as follows: • We continued to cooperate with NASA MPLNET. We used online meeting with the chair of MPLNET and the main engineering staff for discussing data retrieval techniques, inspecting Asian reference station, calibrating the WFR equipment, and educating the techniques on calibrating and replacing components. We also hold the training course for stations and equipment maintenance. • To enhance International collaboration between Taiwan and the US, NASA MPLNET Dr. Welton provides an official letter to declare the EPA-NCU site has been selected as a reference station to support MPLNET sites over Asia. • We set up all the Micro-pulse lidar systems in EPA-NCU - Asian reference station during summer, including cleaning up the instrument, testing the function of instruments, and collecting inter-comparison data with standard systems for the annual maintenance. We also built and executed the operation and maintenance of four stations in Taiwan. • We offered the phased planning of Taiwan Micro-Pulse Lidar Monitoring Network. We also provided advices about Micro-pulse lidar systems and sun photometers, evaluation of related equipment, and environmental safety information about the stations. • We had executed the AP/DC calibration and data QA/QC procedure on schedule to ensure the availability and stability of MPL data. The MPL data has been posted to webpages and database real time and update to EPA server simultaneously. • We applied a statistical method to define the high pollution events in this year and set up a database for case studies. We systematically analyze those pollution events with observational data obtained from EPA MPL system and air quality monitoring stations in Taiwan. We explained the causes of high pollution events based on multiscale analysis including vertical and horizontal distribution of particulate matters and meteorological conditions. The results from those case studies significantly improve our understanding on the air quality deterioration.

Micro pulse lidar (MPL), Aerosol vertical distribution, International collaboration