Investigating the quality of modeled aerosol profiles based on combined lidar and sunphotometer data

Abstract

Abstract. In this study we present an evaluation of the Comprehensive Air Quality Model with extensions (CAMx) for Thessaloniki using radiometric and lidar data. The aerosol mass concentration profiles of CAMx are compared against the PM 2.5 and PM 2.5−10 concentration profiles retrieved by the Lidar-Radiometer Inversion Code (LIRIC). The CAMx model and the LIRIC algorithm results were compared in terms of mean mass concentration profiles, center of mass and integrated mass concentration in the boundary layer and the free troposphere. The mean mass concentration comparison resulted in profiles within the same order of magnitude and similar vertical structure for the PM 2.5 particles. The mean centers of mass values are also close, with a mean bias of 0.57 km. On the opposite side, there are larger differences for the PM 2.5−10 mode, both in the boundary layer and in the free troposphere. In order to grasp the reasons behind the discrepancies, we investigate the effect of aerosol sources that are not properly included in the model's emission inventory and in the boundary conditions such as the wildfires and the desert dust component. The identification of the cases that are affected by wildfires is performed using wind backward trajectories from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model in conjunction with satellite fire pixel data from MODerate-resolution Imaging Spectroradiometer (MODIS) Terra and Aqua global monthly fire location product MCD14ML. By removing those cases the correlation coefficient improves from 0.69 to 0.87 for the PM 2.5 integrated mass in the boundary layer and from 0.72 to 0.89 in the free troposphere. The PM 2.5 center of mass fractional bias also decreases to 0.38 km. Concerning the analysis of the desert dust component, the simulations from the Dust Regional Atmospheric Model (BSC-DREAM8b) were deployed. When only the Saharan dust cases are taken into account, BSC-DREAM8b generally outperforms CAMx when compared with LIRIC, achieving a correlation of 0.91 and a mean bias of −29.1 % for the integrated mass in the free troposphere and a correlation of 0.57 for the center of mass. CAMx, on the other hand, underestimates the integrated mass in the free troposphere. Consequently, the accuracy of CAMx is limited concerning the transported Saharan dust cases. We conclude that the performance of CAMx appears to be best for the PM 2.5 particles, both in the boundary layer and in the free troposphere. Sources of particles not properly taken into account by the model are confirmed to negatively affect its performance, especially for the PM 2.5−10 particles.

Are EARLINET and AERONET climatologies consistent? The case of Thessaloniki, Greece

“…The WCT transformation has also been applied successfully in the past on other lidar products. Siomos et al (2017), for example, use an adaptation of the WCT method and calculate the geometrical features from the aerosol concentration profiles. The transform is provided by Eq.…”

“…The knowledge of the climatological behavior of particles in the troposphere can be utilized in many different ways. Its applications can range from purely scientific, such as the validation of aerosol transportation and air quality models (e.g., Binietoglou et al, 2015;Siomos et al, 2017) and satellite instruments (e.g., Balis et al, 2016), to civilly oriented, for example the impact of the aerosol load on human health (e.g., Mauderly and Chow, 2008;Löndahl et al, 2010), airfare safety (e.g., Brenot et al, 2014), and agriculture (e.g., Gerstl and Zardecki, 1982).…”

“…An additional Raman channel at 607 nm was added in 2008. Another elastic channel at 1064 nm plus one parallel and one cross-polarization channel at 532 nm were added in 2012 (Siomos et al, 2017). The final products, which derived from the raw lidar data processing (see Sect.…”

GARRLiC and LIRIC: strengths and limitations for the characterization of dust and marine particles along with their mixtures

“…For example, LIRIC has been tested for dust and volcanic aerosols (Wagner et al, 2013), dust-pollution mixture (Tsekeri et al, 2013), dust, pollution and a mixture of dust, smoke and pollution (Granados-Muñoz et al, 2014, 2016aPapayannis et al, 2014) and smoke-pollution mixture (Kokkalis et al, 2017). LIRIC has also been used to study dust transport events and dust modelling performance over Europe (Binietoglou et al, 2015;Granados-Muñoz et al, 2016b), as well as to evaluate air quality models (Siomos et al, 2017). GARRLiC has been tested for dust and smoke (Lopatin et al, 2013) and dust aerosols Benavent-Oltra et al, 2017).…”

Are EARLINET and AERONET climatologies consistent? The case of Thessaloniki, Greece

“…The knowledge of the climatological behavior of particles in the troposphere can be utilized in many different ways. Its applications can range from purely scientific, such as the validation of aerosol transportation and air quality models (Binietoglou et al, 2015;Siomos et al, 2017) and satellite instruments (Balis et al, 2016) to civil oriented, for example the impact of the aerosol load on 10 human health (Mauderly and Chow, 2008;Löndahl et al, 2010), airfare safety (Brenot et al, 2014) and agriculture (Gerstl and Zardecki, 1982).…”