1. Observations of aerosol concentration, properties and chemical composition Sandro Fuzzi Institute for Atmospheric Sciences and Climate National Research Council Bologna, Italy

2. Bologna on a typical summer day

3. Measuring aerosol properties Contrary to gaseous molecules whose presence in the atmosphere is univocally defined by one number (concentration), atmospheric aerosol is composed by a population of particles, each one with its own nature and properties

4. Atmospheric particles

5. Measurement principles absorb and scatter visible light, absorb and emit IR radiation, absorb UV light; grow up upon absorption of water vapor; can be seen using an optical or an electronic microscope; can be collected up to weighable mass; are made up of compounds which can be analyzed by chemical methods; can be ionized in a mass spectrometer. Aerosols … Moreover, there are a number of methods to determine specific aerosol components (radionuclides, trace elements, biological particles)

6. In-situ measurements and remote sensing in-situ Advantages: detailed information on the aerosol size-distribution and chemical composition. Ground- based platform ideal for monitoring purposed. Disadvantages: limited spatial and time coverage (especially in the FT and over the oceans) Remote sensing (only optical methods) 1) Columnar properties of the aerosol using photometers and radiometers; 2) Aerosol concentration vertical profile from laser back-scattering (LIDAR)

7. Aerosol number/mass concentration ranges

8. AEROSOL BULK MEASUREMENT SIZE-SEGREGATED MEASUREMENT SINGLE-PARTICLE ANALYSIS Aerosol sampling for chemical analysis

9. Measurement strategy 1.MONITORING NETWORKS: a.for Air Quality b.for Climate 2.FIELD CAMPAIGNS

10. Lat.N 27°57' Lon. E 86°48‘ Altitude 5079 m asl http://evk2.isac.cnr.it Lat.N 27°57' Lon. E 86°48‘ Altitude 5079 m asl http://evk2.isac.cnr.it The Pyramid Observatory in the Himalayas