Improved urban canopy model in WRF and applications:  We found the official released urban canopy model (UCM) coupled to WRF, may not only lead to over- or underestimation of urban fraction and AH in urban and non-urban areas, but spatial variation also affects the model-estimated temperature. To overcome the abovementioned limitation, we modified to consider the 2-D urban fraction and AH (WRF-UCM2D). WRF-UCM2D performed much better than WRF-UCM at non-urban stations with low urban fraction during nighttime. The achievement of this study has a crucial implication for assessing the impacts of urbanization on weather, air quality and regional climate.

Long-range transport of air pollutants to Taiwan: In the winter and spring times, the cold continental airs not only often outflow to Taiwan, but also bring air pollutants and dusts after frontal passage. Moreover, springtime happens to be the biomass burning season in Indochina peninsula (Indochina). Under favor weather conditions, the products of biomass burning pollutants could be transported easily to Taiwan and even East Asia. Due to the unique geographic location of Taiwan, that allows us to receive more than just one source in spring. The impacts are also essential and complex.

We first demonstrated that the leeside troughs over Indochina play a dominant role in the uplift of the pollutants below 3 km, and that the strong westerlies prevailing above 3 km transport those pollutants  to Taiwan. Moreover, we successfully simulated and evaluated the radiative impact of biomass burning produces aerosols and air pollutants to Taiwan during springtime in Southeast Asia. Under the influence of biomass-burning aerosol plume transported by strong wind, there is a NE-SW zone stretching from southern China to Taiwan with reduction in shortwave radiation of about 20 Wm^-2 at ground surface during study period. Such significant reduction in radiation attributed to biomass-burning aerosols and their impact on the regional climate in East Asia merit attention.

Regional Climate Changes study: It is difficult and inadequate to use a global model alone for projecting future climate changes such as Taiwan, a complex geographic nature island, due to its coarse resolution. We have performed dynamic downscaling of Taiwan’s climate in the recent past (1979-2003) and climate change projection for the near and distant future (2015-2039 and 2075-2099, respectively) by using the WRF model. The simulation is forced by the global model, ECHAM5/MPIOM. Projection of future climate changes revealed both altitudinal and latitudinal variations in warming trend, with more significant temperature increase in mountain areas than in plain areas toward the end of the 21st century and more obvious warming in the north than in the south of Taiwan. The results obtained in this study can be applied to other regions of similar latitudes and with comparable relief.