title: Seasonal and long term variations of surface ozone concentrations in Malaysian Borneo.
abstract: Malaysian Borneo has a lower population density and is an area known for its lush rainforests. However, changes in pollutant profiles are expected due to increasing urbanisation and commercial-industrial activities. This study aims to determine the variation of surface O3concentration recorded at seven selected stations in Malaysian Borneo. Hourly surface O3data covering the period 2002 to 2013, obtained from the Malaysian Department of Environment (DOE), were analysed using statistical methods. The results show that the concentrations of O3recorded in Malaysian Borneo during the study period were below the maximum Malaysian Air Quality Standard of 100ppbv. The hourly average and maximum O3concentrations of 31 and 92ppbv reported at Bintulu (S3) respectively were the highest among the O3concentrations recorded at the sampling stations. Further investigation on O3precursors show that sampling sites located near to local petrochemical industrial activities, such as Bintulu (S3) and Miri (S4), have higher NO2/NO ratios (between 3.21 and 5.67) compared to other stations. The normalised O3values recorded at all stations were higher during the weekend compared to weekdays (unlike its precursors) which suggests the influence of O3titration by NO during weekdays. The results also show that there are distinct seasonal variations in O3across Borneo. High surface O3concentrations were usually observed between August and September at all stations with the exception of station S7 on the east coast. Majority of the stations (except S1 and S6) have recorded increasing averaged maximum concentrations of surface O3over the analysed years. Increasing trends of NO2and decreasing trends of NO influence the yearly averaged maximum of O3especially at S3. This study also shows that variations of meteorological factors such as wind speed and direction, humidity and temperature influence the concentration of surface O3.
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: talib@ukm.edu.my.
authors: Mohd Talib
authors: MT
authors: Latif
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia.
authors: Doreena
authors: D
authors: Dominick
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Fatimah
authors: F
authors: Ahamad
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Nur Shuhada
authors: NS
authors: Ahamad
authors: Centre for Tropical Climate Change System (IKLIM), Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Md Firoz
authors: MF
authors: Khan
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Liew
authors: L
authors: Juneng
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Chung Jing
authors: CJ
authors: Xiang
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System (IKLIM), Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Mohd Shahrul Mohd
authors: MSM
authors: Nadzir
authors: Centre of Atmospheric Sciences, Chemistry Department, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
authors: Andrew D
authors: AD
authors: Robinson
authors: School of Marine Science and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
authors: Marzuki
authors: M
authors: Ismail
authors: Centre for Atmospheric Informatics and Emissions Technology, Cranfield University, Cranfield MK43 0AL, United Kingdom.
authors: Mohammed Iqbal
authors: MI
authors: Mead
authors: Centre for Atmospheric Informatics and Emissions Technology, Cranfield University, Cranfield MK43 0AL, United Kingdom.
authors: Neil R P
authors: NRP
authors: Harris
keywords: Meteorological factors; Ozone precursors; Seasonal variations; Surface ozone