Group
|
Email: Education: M.phil., Earth & Atmospheric Sciences, the Chinese University of Hong Kong, 2021. |
Oscar Hiu Fai TAM
Oscar Tam is a graduated MPhil student co-supervised by Prof Amos TAI and Prof Francis TAM.
Before joining EASC, he completed his BSc study in the Department of Physics, The Chinese University of Hong Kong, where he polished computational skills and genuine interest in meteorology.
During his MPhil study, he studied how regional climate and air quality would respond to irrigation using WRF coupled with GEOS-Chem (WRF-GC) over semiarid Northwest China.
Research Interests:
- Numerical models
- Model post-processing
- Land-atmosphere interactions
Recent Research Projects:
(All figures below are subject to copyright, and are allowed to be used only with permission from the owner.)
Irrigation modifies regional climate and air quality by altering surface characteristics including moisture and heat fluxes. Such modification can be substantial when compared with the relatively dry climatic background. Agricultural approaches including the deployment of different irrigation systems can be advised by optimization of water use, which is to strike a balance between irrigation, water availability, crop yields, regional climate and air quality.
In this study, we studied the sensitivity of regional weather and air quality to irrigation method, a state-of-the-art climate-chemistry-land model system namely the Weather Research and Forecast Model (WRF) coupled with the GEOS-Chem (GC) chemical transport model, referred to WRF-GC, with various options to represent land surface and agricultural processes. With its ability to simulate how weather and air pollutants evolve with time, we studied the effects of implementing the “flooded”, “sprinkler”, and “drip irrigation” irrigation schemes on regional climate and air quality.
We found that flooded and sprinkler irrigation practices greatly reduce the sensible heat flux and increase the latent heat flux. Flooded irrigation can induce cooling of the surface up to 2°C as inferred from the averaged drop in near surface air temperature. Consequently, planetary boundary layer height decreases, which inhibits vertical mixing of air pollutants and deteriorates surface air quality. In particular, surface NOx concentration increases by ~0.6 ppb (12%) if flooded irrigation is adopted near Xi’an of Shaanxi province. On the contrary, air quality worsening is minimized if drip irrigation is adopted, which is attributable to the minimal changes in regional climate. We conclude that drip irrigation is likely the most preferable option for semiarid agriculture, not only because of its water-saving potential but also its minimal impacts on the atmospheric environment.
