Microphysical characterization of long-range transported biomass burning particles from North America at three EARLINET stations

Abstract

Abstract. Strong events of long-range transported biomass burning aerosol were detected during July 2013 at three EARLINET (European Aerosol Research Lidar Network) stations, namely Granada (Spain), Leipzig (Germany) and Warsaw (Poland). Satellite observations from MODIS (Moderate Resolution Imaging Spectroradiometer) and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) instruments, as well as modeling tools such as HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) and NAAPS (Navy Aerosol Analysis and Prediction System), have been used to estimate the sources and transport paths of those North American forest fire smoke particles. A multiwavelength Raman lidar technique was applied to obtain vertically resolved particle optical properties, and further inversion of those properties with a regularization algorithm allowed for retrieving microphysical information on the studied particles. The results highlight the presence of smoke layers of 1-2 km thickness, located at about 5 km a.s.l. altitude over Granada and Leipzig and around 2.5 km a.s.l. at Warsaw. These layers were intense, as they accounted for more than 30 % of the total AOD (aerosol optical depth) in all cases, and presented optical and microphysical features typical for different aging degrees: color ratio of lidar ratios (LR 532 / LR 355 ) around 2, α-related ångström exponents of less than 1, effective radii of 0.3 µm and large values of single scattering albedos (SSA), nearly spectrally independent. The intensive microphysical properties were compared with columnar retrievals form co-located AERONET (Aerosol Robotic Network) stations. The intensity of the layers was also characterized in terms of particle volume concentration, and then an experimental relationship between this magnitude and the particle extinction coefficient was established.

A fully autonomous ozone, aerosol and nighttime water vapor lidar: a synergistic approach to profiling the atmosphere in the Canadian oil sands region

“…The S ratio plotted as a 10 min average shows extraordinary detail within the smoke plume, with values ranging approximately from 40 to 65 sr. These values are consistent with the value of 45 to 65 sr reported by Barbosa et al (2014) and are consistent with several other observations provided in Table 3 of Ortiz-Amezcua et al (2017). Figure 16 also shows the boundary layer aerosols with an S ratio of 20 to 35 sr, indicative of larger particles in the moist boundary layer air (see water vapor plot in Fig.…”

“…For details of the intercomparison refer to a separate publication (manuscript in preparation). Lidar networks (http://ndacc-lidar.org, last access: 14 November 2018; http://mplnet.gsfc.nasa.gov, last access: 14 November 2018; Papayannis et al, 2008;Sugimoto and Uno, 2009) are very important scientific tools that allow the collective benefit of increased geographical coverage (Langford et al, 2018;Trickl et al, 2016) and can often provide valuable climatological data (Granados-Muñoz and Leblanc, 2016;Khaykin et al, 2017;Gaudel et al, 2015). The existence of networks like TOLNet will help to address the need for more ozone profilers in the troposphere as reported in the recent Tropospheric Ozone Assessment Report (TOAR) by Gaudel et al (2018).…”

Ground/space, passive/active remote sensing observations coupled with particle dispersion modelling to understand the inter-continental transport of wildfire smoke plumes

“…The layer mean values of p  are 0.04 and 0.12 in the mid-and upper troposphere, respectively. While the mid troposphere value falls in the range of literature values(Ortiz-Amezcua et al, 2017) and indicate spherical or almost spherical smoke particles, the value of 0.12 in the upper troposphere is rather unusual. Some works investigating the inter-continental transport of North American fire smoke to Europe from August 2017 also report unusually high depolarization ratios(Khaykin et al, 2018;Haarig et al, 2018;Hu et al, 2018;Sicard et al, 2018) up to 0.20 at 532 nm in the stratosphere.…”

Hygroscopic growth study in the framework of EARLINET during the SLOPE I campaign: synergy of remote sensing and in situ instrumentation

“…The main local sources are road traffic, domestic heating (during wintertime), and biomass burning . Transported smoke principally from North America, northern Africa, and the Iberian Peninsula can also affect the study area NavasGuzmán et al, 2013;Preißler et al, 2013;Pereira et al, 2014;Ortiz-Amezcua et al, 2017). Moreover, the probability of marine particles reaching the city is low despite the short distance to the coast (about 50 km away) due to the orography of the region, with mountains blocking the path from the sea to the city.…”