Special Lecture on “Development of explicit photochemical modeling and its application in Asia Pacific region” by Dr. Sean Lam

You are cordially invited to a special lecture on “Development of explicit photochemical modeling and its application in Asia Pacific region” by Dr. Sean Lam, Senior Air Quality Engineer, Pacific Environment Limited, Australia. It will be held as follow:

Date: Thursday, 15 October 2015
Time: 15:00-16:00 hrs.
Place: S-101 (SERD’s Meeting room)


A photochemical model incorporating the highly explicit Master Chemical Mechanism (MCM) is developed to investigate regional chemical characteristics.

Adopting the available emission data in the region, the model is capable to determine the photochemical ozone creation potentials (POCPs) for various airsheds around the world. The POCPs provides a means of ranking the regional emission contributions of individual Volatile Organic Compounds (VOC) to ozone (O3) formation. POCPs for specific regions can provide a sound scientific foundation for policy makers to determine emissions limitation and reduction strategies.

In addition, a top­down approach was adopted to evaluate secondary pollutants formation, i.e. O3, attributed to different emission sources. A number of features are enhanced in this model including the photolysis rates and the hourly varying speciated VOC concentration input from on site sampling. The combined model gives a reasonably good representation of high O3 levels in the region. The model successfully captured a multi­day O3 event in Hong Kong during the autumn, 2010.

Source apportionment via Positive Matrix Factorization (PMF) was carried out on the sampled VOC data, to determine the major sources in the region. Based on the outcomes of the PMF a sensitivity analysis using the developed photochemical model was conducted and used to estimate O3 reduction under different source removal regimes. By using a combined field measurements and modelling approach, this study has demonstrated a potentially effective secondary pollutants control methodology to strategize the priority of emission reduction for air quality policy.

Faculty, staff and students of related fields of study are strongly encouraged to participate. Please see attached file for your information and reference.