Linking the meteorological conditions to air pollution in Italy Massimo D’Isidoro, Mihaela Mircea ENEA, National Agency for New Technologies, Energy and Sustainable Economic Development, via Martiri di Monte Sole 4, 40129, Bologna, Italy 17th Task Force on Measurement and Modelling Meeting 18 - 20 May 2016 in Utrecht, Netherlands

Outline daily exceedances of PM10 and NO2 limit values and associated atmospheric circulation types (CTs) evaluation of spatial extension and concomitance of exceedances at monitoring stations in Po valley selection of an acute pollution event for PM10 and of alternative meteorological conditions impact of meteorology on PM10 and its components with AMS-MINNI summary of results

PM10 concentrations at Milan and atmospheric circulation types (Valverde et al. 2014, software COST 733&ERA-Interim reanalysis data CT2(VCT1&3),CT4(VCT5),CT5(VCT2),CT6(VCT4&VCT6)

PM10 concentrations at Milan and circulation types daily 50 μg/m3 exceeded more than 35 times a calendar year! (Directive 50/2008)

NO2 concentrations at Milan and circulation types 200 μg/m3,not exceeded more than 18 times a calendar year (Directive 50/2008)

Exceedances of PM10 limit value at Bologna and Milan: background stations

Exceedances of PM10 limit value at traffic stations in Bologna and Milan: selection of an acute pollution event

Alternative meteorological conditions according to daily CT 28 January-1 February 2010 1-5 January 2003 13-17 February 2005 24-28 January 2007 24-28 December 2007

Probing the atmosphere at urban and rural stations Urban stations: Milano-Verziere and Bologna-San Felice Rural stations: Tavazzano and San Pietro Capofiume

Temperature and wind speed for the selected meteorological periods

Impact of meteorological conditions on PM10 concentrations: AMS-MINNI 29&30 January 2010 2010, 2003: CT4 2005, 2007j: CT2 2007d: CT6

Differences in PM10 components, temperature and wind speed: 2005 -2010

Differences in PM10 concentrations: 2005 - 2010 29 January 2010 mg/m3 30 January 2010 mg/m3

Differences in temperature, wind speed and PM10 concentrations at Bologna-San Felice 30 January 2010 2010, 2003: CT4 2005, 2007g: CT2 2007d: CT6

Differences in temperature, wind speed and PM10 concentrations at Milan-Verziere 29 January 2010 2010, 2003: CT4 2005, 2007g: CT2 2007d: CT6

Differences in temperature, wind speed, mixing layer height and PM10 concentrations during the days with exceedances 2007j 2003 2005 2007d DT(C) - bubble 2003 2007j 2007d 2005 DT(C) - bubble 2007j 2005 2007d 2003: -143 m DHmix(m) - bubble 2003: -115 m 2007j 2007d 2005 DHmix(m) - bubble

Differences in PM10 due to emissions reductions

Summary of results the decrease of concentrations due to meteorological conditions were from 45 to 66 mg/m3 at Bologna and from 68 to 114 mg/m3 at Milan during the days with maximum exceedances. during these days, the PM10 concentrations decrease with the increase of the wind speed, but no relationship with temperature is evident substantial decreases of primary anthropogenic aerosols is observed at urban stations (APANT and POA) while the decrease of inorganic secondary aerosols (ANO3 and ANH4 mainly) is observed at both urban and rural stations the relationship between the circulation type and PM10 exceedances is weak/qualitatevely: local effects are dominant? impact of meteorology is 10 times higher than the impact of 20% reduction of emissions (primary anthropogenic aerosols and gas precursors) further investigation on local dynamical and thermodynamical parameters ….

Circulation Types