Influence of Meteorological Conditions and Fire Hotspots on PM0.1 in Northern Thailand During Strong Haze Episodes and Carbonaceous Aerosol Characterization

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Influence of Meteorological Conditions and Fire Hotspots on PM0.1 in Northern Thailand during Strong Haze Episodes and Carbonaceous Aerosol Characterization

Chaiyoth Sresawasd1,2, Thaneeya Chetiyanukornkul3, Phuchiwan Suriyawong3, Surajit Tekasakul4, Masami Furuuchi5, Mitsuhiko Hata5, Rachane Malinee1,2, Perapong Tekasakul1,6 and Racha Dejchanchaiwong1,7*

1Air Pollution and Health Effect Research Center, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand 2Energy Technology Program, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand. 3Department of Biology, Faculty of Science, Chiang Mai University, Mueang, Chiang Mai, 50200, Thailand 4Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand 5Faculty of Geoscience and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan 6Department of Mechanical and Mechatronics Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand 7Department of Chemical Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand

∗ Corresponding author. Tel: +66-89-730-8887; Fax: +66-74-558830 E-mail address: [email protected]

Table S1 Air sampling during the haze and non-haze periods in 2017 to 2019 Period Sampling period Sample Code 2017 haze 3-5 Apr 2017 Apr_17 1-3 May 2017 May_17 19-21 June 2017 Jun_17 2017-2018 7-9 August 2017 Aug_17 Non-haze 4-6 September 2017 Sep_17 2-4 October 2017 Oct_17 4-6 December 2017 Dec_17 5-7 February 2018 Feb_18 5-7 March 2018 Mar_18_#1 2018 haze 19-21 March 2018 Mar_18_#2 2-4 April 2018 Apr_18_#1 16-18 April 2018 Apr_18_#2 12-13 March 2019 Mar_19_#1 14-15 March 2019 Mar_19_#2 15-16 March 2019 Mar_19_#3 2019 haze 16-17 March 2019 Mar_19_#4

21-22 March 2019 Mar_19_#5 24-25 March 2019 Mar_19_#6 25-26 March 2019 Mar_19_#7

Table S2 PM0.1 concentration, meteorological parameters and numbers of fire hotspots during sample collection periods 2017-2019. Year Month PM0.1 Precipitation RH Temp. WS Hotspots (µg m-3) (mm) (%) (°C) (m s-1) (points) April 6.6 4.1 63.2 28.4 6.6 1503 2017 May 5.2 2.7 71.6 28.5 7.3 480 June 4.0 4 75.9 27.9 6.7 2 August 6.2 43.1 78.0 27.4 7.9 0 September 3.4 59.3 78.7 27.5 6.7 0 October 3.8 31.4 79.2 26.6 7.5 0 December 4.4 0 70.8 22.7 3.9 95 February 3.9 0 63 23.4 5.3 1969 2018 March 15.5±2.0 0 54.5 27.7 4.5 3285 April 10.4±1.5 8.5 61.6 28.7 8.1 1972 2019 March 13.0±3.0 0 47.1 28.4 4.5 1059 Temp.: Temperature: RH: relative humidity; WS: wind speed.

Fig. S1 Example of the boundary of hotpots influencing the PM concentration at the receptor

Fig. S2 Cumulative fraction of POC and SOC in total OC during 2017-2018-2019 and 2017- 2018 non-haze periods in Chiang Mai, Thailand

Fig. S3 Distributions of carbonaceous components in PM0.1 during 2017-2018-2019 haze and 2017-2018 non-haze periods in Chiang Mai, Thailand.

(a) 3 April 2017 (b) 19 March 2018

(e) 7 August 2017 (f) 2 October 2017

Fig.S4 48-hr backward trajectories at 1,000 m AGL during 2017-2018-2019 haze and 2017-2018 non-haze periods.