Sinusoidal and cosinusoidal variables were generated to incorporate the effect of the time of the
day. The effect of day of the week was considered using a suitable arithmetic index26, in order to
account for the short-term variability of emissions. PM10 concentrations lagged by 24, 25 and 26
hours were also used as input variables for the estimation of PM10 concentrations 24-h in
Wind Speed-WS X X X X
Ambient Temperature- T X X X
Relative Humidity- RH X X
Barometric Pressure- P X X X
Rainfall- RF
Solar Radiation- SR X X
Sine of the wind Direction- sWD
Cosine of the wind direction- cWD X X
Day of the Week index- DoW X X X X
Seasonal index- SEA X X X
Sine of the hour of the day- SDAY
Cosine of the hour of the day-