Abstract:

Making progress in understanding air quality requires the iterative application of knowledge gained from emission inventory, air quality monitoring and modelling. Following this progression, Hong Kong established an air quality modelling system named PATH (Pollutants in the Atmosphere and their Transport over Hongkong) in 2001 to simulate historical air quality episodes. The system interfaces off-the-shelf comprehensive simulation modules of emissions, meteorology and air quality chemistry and is set up with nested grid (grid spacing of 40.5, 13.5, 4.5, 1.5 and 0.5km) over a large part of southern Asia, reaching to Nepal (west), the western Pacific (east), central China (north) and the Philippines (south).

Since its inception, the system, originally designed for simulating past episodes, has been further developed to make air quality forecast of up to 48 hours. This was enabled by access to weather forecast from the Hong Kong Observatory and the lastest computer technologies.

In this real-time / forecast mode, the model has been able to simulate close to the reality and the long term air quality trends and the users were able to track model performance over a much longer time frame - years, apply statistical analyses to identify and prioritise areas requiring improvements and feed back to the holders of this information (e.g. emissions and meteorology) for action. This sets in motion a series of improvement works aimed at gaining a better understanding of the air quality of the whole region. While this is going on, the system is used to answer a host of regulatory, policy and assessment questions on air quality in and around Hong Kong.

Presentation: http://www.cleanairnet.org/baq2006/1757/docs/SW4_3.ppt