Table 5.

ML estimates of BSM parameters and variances for NO${}_2$.

	Parameter	Marche	Citta Studi	Liguria	Verziere	Senato
log(Pavia)	$\theta$	0.36 ***	0.85 ***	0.69 ***	0.65 ***	0.55 ***
		(0.01)	(0.02)	(0.02)	(0.02)	(0.01)
Holidays	${\varphi }_1$	−0.06 ***	−0.08 ***	−0.08 ***	−0.10 ***	−0.08 **
		(0.02)	(0.03)	(0.02)	(0.02)	(0.03)
Week-end	${\varphi }_2$	−0.06 ***	−0.10 ***	−0.09 ***	−0.14 ***	−0.11 ***
		(0.01)	(0.01)	(0.01)	(0.01)	(0.01)
Saturday:Holidays	${\varphi }_3$	0.06	0.18 ***	0.06	0.14 **	−0.09 ***
		(0.05)	(0.08)	0.07	(0.06)	(0.02)
Sunday:Holidays	${\varphi }_4$	0.08 ***	0.11 ***	0.11 ***	0.06	0.10 ***
		(0.03)	(0.05)	(0.04)	(0.03)	(0.03)
WindSpeed Q${}_{\mathrm{SW}}$	${\varphi }_5$	−0.35 ***	−0.13 ***	−0.42 ***	−0.23 ***	−0.18 ***
		(0.01)	(0.01)	(0.01)	(0.01)	(0.01)
WindSpeed Q${}_{\mathrm{NW}}$	${\varphi }_6$	−0.17 ***	−0.16 ***	−0.08 ***	−0.13 ***	−0.08 ***
		(0.01)	(0.01)	(0.01)	(0.01)	(0.01)
Level variance	${\sigma }_{\eta }^2$	0.0051	0.0065	0.0046	0.0044	0.0024
Slope variance	${\sigma }_{\zeta }^2$	0.0000	0.0000	0.0000	0.0000	0.0000
Seasonality variance	${\sigma }_{\omega }^2$	0.0000	0.0000	0.0000	0.0000	0.0000
Errors variance	${\sigma }_{\epsilon }^2$	0.0093	0.0282	0.0182	0.0154	0.0114

Note 1: values in parenthesis are standard errors. Note 2: ** p < 0.05, *** p < 0.01.