PM measurement campaign HOVERT in the Greater Berlin area: model evaluation with chemically specified particulate matter observations for a one year period

[摘要] The HOVERT (HOrizontal and VERtical Transport of ozone and particulatematter) campaign held in the Berlin Brandenburg area in Eastern Germany fromSeptember 2001 to September 2002 allowed to collect a unique data set of theaerosol chemical speciation (daily averages) at traffic, urban and ruralsites. These observations are used for a thorough evaluation of the aerosolpart in the REM-CALGRID model (RCG) developed at the Free University ofBerlin (FUB). For inorganic ions (sulphate, nitrate and ammonium), simulatedannual averages agree to observations within ±30% at more than half ofthe sites and always within a factor of two. Correlation coefficients arelarger than in previous studies for SO₄²⁻ and NH₄⁺ (>0.7). For nitrate, less elevated correlations, 0.4–0.7 in the cold season,0.2–0.4 in the warm season, are encountered. To our knowledge, this is oneof the first comparisons of air quality model simulated elemental andorganic carbon (EC and OC) with daily observations for a whole year. Itsuggests an overestimation of EC and OC emissions in the Berlin area(through a scaling techniques between EC, OC and NO_x and when assumingcorrect NO_x emissions), and an underestimation of EC and OC at rural sites.Secondary organic aerosol (SOA) formation, recently introduced into themodel (SORGAM module, Schell et al., 2001), is simulated as a very variableprocess, SOA levels varying from close to zero for most days to more than 5 μg/m³.Correlation between simulated SOA to observed OC is about 0.6,indicating that simulated variability partly corresponds to reality.

[学科分类] 大气科学