Influence of Biomass Burning on Temporal and Diurnal Variations of Acidic Gases, Particulate Nitrate, and Sulfate in a Tropical Urban Atmosphere

Table 1

Statistical summary of air quality (unit: μg m⁻³), meteorology, and PSI on a 24 hr basis.

Species	𝑁	Mean	S.D.	Min	Max
SO2	239	17.9	10.8	1.7	54.9
HONO	239	3.1	1.8	0.9	8.2
HNO3	239	0.6	0.5	0.1	3.5
SO4^∗2−	239	5.3	4.7	1.1	34.8
NO3^−	239	1.0	1.2	0.1	9.6
𝑇 (°C)	239	27.2	1.1	24.5	29.6
RH (%)	239	81.2	5.8	73.3	97.8
WS (m s^−1)	239	2.8	1.1	0.6	5.3
WD (°)	239	162.7	46.6	64.7	316.3
PSI	239	55	18	18	139

∗The concentrations are reported for non-sea-salt particles; 𝑁: number of valid 24 hr observations; S.D.: standard deviation; Min: minimum; Max: maximum; 𝑇: temperature; RH: relative humidity; WS: wind speed; WD: wind direction; PSI: Pollutant Standards Index.