Table 1: Pearson correlation coefficients between selected parameters.

Corr( 𝑋 , 𝑌 )Pollutant
SPMSO2NO2O3

SO20.731
NO20.7820.817
O30.4290.014−0.054
Temp−0.3870.5850.5870.178
Mean RH0.6250.528−0.4820.407
Wind speed−0.0960.069−0.083−0.140
Sunshine Hr0.081−0.032−0.0800.315*
Air pressure0.1430.1470.1640.055

Bolded values were used in this model; *sunshine hour has a close relationship with O3 level, so sunshine hour was selected to be one of the input variables for O3 model.