Model Evaluation and Scale Issues in Chemical and Optical Aerosol Properties over the Greater Milan Area (Italy), for June 2001

We study scale issues in aerosol modelling, using the mesoscale Transport Atmospheric Pollutants Model (TAPOM) at three horizontal resolutions (5x5km, 10x10km and 20x20km) through calculations of aerosol optical depth (AOD) and other aerosol properties for the Milan area in Italy during June 2001. A comparison of the AOD calculations is made with several data sets. Satellite data from both the MISR and MODIS instruments on board the Terra platform are used, as well as sun photometer data from both the AERONET and the Swiss CHARM networks. A finer model resolution shows a more detailed AOD distribution pattern following the domain’s orography, however when compared to measurements finer resolutions do not produce a significant improvement of model results. For dry, clear sky days the calculated AOD values for the 5x5km and 10x10km resolutions are somewhat underestimated by the model when compared to sun photometer and satellite data. For other days the model strongly underestimates measured AOD from satellite and sun photometer, though we find for some days a fairly good correlation between calculated and observed AOD profile. Our analysis is complicated by the fact that significant differences are found between remote sensing AOD retrievals for the same area and time frame. A likely reason for the discrepancy between modelled and observed is the presence of haze or cirrus clouds and Saharan dust, but we can not exclude that the modelled aerosol concentrations are in general too low.

DE MEIJ Alexander;  WAGNER S.;  CUVELIER Cornelis;  DENTENER Franciscus;  GOBRON Nadine;  THUNIS Philippe;  SCHAAP M.; 

De Meij A, Wagner S, Cuvelier C, Dentener F, Gobron N, Thunis P, Schaap M. Model Evaluation and Scale Issues in Chemical and Optical Aerosol Properties over the Greater Milan Area (Italy), for June 2001. ATMOSPHERIC RESEARCH 85 (2); 2007. p. 243 - 267. JRC33948

2007-11-21

ELSEVIER SCIENCE INC

JRC33948

0169-8095,   

http://www.sciencedirect.com/science/journal/01698095,    https://publications.jrc.ec.europa.eu/repository/handle/JRC33948,   

10.1016/j.atmosres.2007.02.001,