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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:01 |
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Conference: Bucharest University Faculty of Physics 2019 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Use of lidar data to identify predominant aerosol types in Europe during 2008-2018
Authors:
Victor NICOLAE (1,2), Sabina ȘTEFAN (2), Doina NICOLAE (1), Jeni VASILESCU (1), Bogdan ANTONESCU (1), Simona ANDREI (1), Dragoș ENE (1)
*
Affiliation:
1) Institutul Național de Cercetare-Dezvoltare pentru Optoelectronică INOE 2000
2) Universitatea din București, Facultatea de Fizică
E-mail
ihlades@gmail.com
Keywords:
lidar
photometry
aerosol
typing
Abstract:
This study presents the aerosol typing algorithm using multiwavelength Raman lidar data (NATALI) and uses it algorithm to identify the different types of aerosols over Europe between 2008 and 2018. The NATALI algorithm is based upon the neural networks ability to resolve overlapping intensive optical parameters which are computed for each layer identified in the multiwavelength Raman lidar vertical profiles.
The aerosols over Europe were characterized using lidar and photometry data collected between 2008 and 2018 by the EARLINET and AERONET networks. 17 stations have been selected and grouped in 5 different clusters.
Through this analysis I determined that the typical aerosol that can be observed over Europe between 2008 and 2018 is a medium-sized particle, with medium absorbtion properties and with a low spectral dependency. It has a significant variability over time (season-to-season as well as year-to-year) but it does not vary significantly with distance, being primarily influenced by long-range transport from other continents and the metheorological elements.
Smoke is predominant in the East (38% of all observed layers), but it can be found in Iberia (30%) and the mediterranean region (29%) as well, due to frequent transports from Africa. In Central and Northern Europe the predominant aerosol type is the Continental one (39% and 37%). Dust can be measured all across Europe, especially in the autumn (18%) and the spring time (13%), being lifted by the turbulent air mass over the PBL. Continental polluted aerosols still play a significant role in Europe (18%), but the decreasing trend of the AOD suggests that new environment legislation is working.
Hot years in Europe (2011-2015) are linked with an increase in Angstrom exponent values, measured by AERONET, as well as an increasing proportion of smoke particules found by NATALI using the EARLINET observations.
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