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Indirect aerosol hygroscopic growth observations with a backscattering lidar, part II: Five day breeze onset data analyses

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Autor(es):
Rodrigues, Patricia Ferrini ; Landulfo, Eduardo ; Gandu, Adilson Wagner ; da Silva Lopes, Fabio Juliano ; da Costa, Renata Facundes ; Nakaema, Walter ; Singh, UN ; Pappalardo, G
Número total de Autores: 8
Tipo de documento: Artigo Científico
Fonte: LIDAR TECHNOLOGIES, TECHNIQUES, AND MEASUREMENTS FOR ATMOSPHERIC REMOTE SENSING VII; v. 8182, p. 9-pg., 2011-01-01.
Resumo

Atmospheric aerosol particles have received much attention in recent years due to their importance in climate change. The influence of these particles on Earth's radiative budget depends on a number of factors, including their size distribution and chemical composition. This work addresses a particular property of aerosols, namely, the extent to which they have affinity for water vapor. The size increase of aerosol particles resulting from water vapor uptake has important implications for the direct scattering of radiation and cloud droplets formation. We used a single-wavelength backscatter LIDAR (532 nm), and relative humidity profiles obtained from radiosounding to assess the hygroscopic growing factor of aerosols over Sao Paulo metropolitan region, for five days altogether on March and September 2007 and August 2009. In these days we had a breeze onset over the metropolitan area, potentially bringing marine aerosols and humidity from the Atlantic Ocean. In this way we were able to detect a change in the boundary layer aerosol optical properties during these onsets using range corrected backscattering signal from LIDAR and a detailed analysis on the changes in backscattering coefficient profiles by a Klett analysis. In order to infer the hygroscopic growing factor, we developed a fitting model algorithm, proposed in the literature, calculating the backscattering coefficient at 532 nm for periods before and during the breeze and comparing the same profiles at various altitude levels with a reference profile at the lowest relative humidity level whithin the mixing layer. In addition, we performed a comparison between the thirty minutes backscattering profiles inside the breeze with a reference thirty minutes backscattering profile before the breeze. (AU)

Processo FAPESP: 09/16001-0 - Avaliação da higroscopicidade de aerossóis em atmosferas urbanas pela técnica de LIDAR
Beneficiário:Eduardo Landulfo
Modalidade de apoio: Auxílio à Pesquisa - Regular