Retrieval of aerosol complex refractive index from a synergy between lidar, sunphotometer and in situ measurements during LISAIR experiment

[摘要] Particulate pollutant exchanges between the streets and the PlanetaryBoundary Layer (PBL), and their daily evolution linked to human activitywere studied in the framework of the LIdar pour la Surveillance de l'AIR(LISAIR) experiment. This program lasted from 10 to 30 May 2005. Asynergetic approach combining dedicated active (lidar) and passive(sunphotometer) remote sensors as well as ground based in situinstrumentation (nephelometer, aethalometer and particle sizers) was used toinvestigate urban aerosol optical properties within Paris. Aerosol complexrefractive indices were assessed to be 1.56–0.034 i at 355 nm and 1.59–0.040 iat 532 nm, thus leading to single-scattering albedo values between 0.80 and0.88. These retrievals are consistent with soot components in the aerosolarising from traffic exhausts indicating that these pollutants have aradiative impact on climate. We also discussed the influence of relativehumidity on aerosol properties. A good agreement was found between verticalextinction profile derived from lidar backscattering signal and retrievedfrom the coupling between radiosounding and ground in situ measurements.

[学科分类] 大气科学