Climate change impacts on surface ozone in Malaysia region

• Main Author: Kong, Soon Kai
• Format: Thesis
• Language: English; English
• Published: 2016
• Subjects: QC81-114 Weights and measures
• Online Access: https://eprints.ums.edu.my/id/eprint/38556/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/38556/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/38556/

Climate change is a significant change of weather pattern over long period of time. The issue is critical for the region which the economics relying on agriculture and natural resources including Malaysia country. The changing climate in the future period triggered by the future emission scenario could influence the ozone concentration, and eventually causing the health problem more pronounce. The present study examine the impact of regional climate change towards the future air quality over the Malaysia region under Representative Concentration Pathway (RCP) scenarios including RCP8.5 and RCP4.5. The primary investigation is focus on the model performance and how the future climate condition can affect the ozone mixing ratio besides the influence of the related oxidants and precursors. A coupled Weather Research Forecast - Community Multiscale Air Quality (WRF-CMAQ) modeling system has been applied by using the meteorological data from Community Earth System Model (CESM) and Model Inter-Comparison Study for Asia (MISC-Asia) emission inventory as main input to the model. Three sets of simulation were performed for each climate scenarios: one was the baseline period (2010) and another two were the future-day period (2050 and 2100), during the winter and summer monsoons. Generally, the simulation of RCP scenarios downscaled by Weather Research Forecast (WRF) modeling system agrees well with Climate Research Unit (CRU) observation and National Centers for Environmental Prediction (NCEP) reanalysis datasets in simulating the surface temperature by producing a good value of statistical analysis. However, the precipitation did not perform well. The future projection under RCP8.5 and RCP4.5 scenarios revealed that the surface temperature increased across Malaysia region in 2050 and 2100, which may associated with the impact of long-live greenhouse gases (GHG) emission. The patterns of total precipitation were varied for both RCP4.5 and RCP8.5 scenarios. The temperature increased under both scenarios lead to the increased of evaporation and thus causing the more precipitation on land area during that specific period. The study also identified the model deficiencies and evaluated the performance of coupled WRF-CMAQ modeling system in simulating air quality in Malaysia region. The simulation of RCP simulations reproduced well the observed dataset from Department of Environment (DOE) and NCEP reanalysis dataset for maximum 1-hour average surface ozone mixing ratio by producing a good value of statistical analysis. In comparison with present scenario, there was a small decrease of the maximum 1-hour average surface ozone mixing ratio under RCP8.5 scenario, but large decrease for RCP4.5 scenario except the winter monsoon. Generally, the decreased of ozone mixing ratio was found to be affected by climate change as well as to the changes of ozone's oxidants such as hydroxyl radical (OH), nitrogen oxides (NOx) and acid