Aerosol Characterization during the Summer 2017 Huge Fire Event on Mount Vesuvius (Italy) by Remote Sensing and In Situ Observations

Abstract

During the summer of 2017, multiple huge fires occurred on Mount Vesuvius (Italy), dispersing a large quantity of ash in the surrounding area ensuing the burning of tens of hectares of Mediterranean scrub. The fires affected a very large area of the Vesuvius National Park and the smoke was driven by winds towards the city of Naples, causing daily peak values of particulate matter (PM) concentrations at ground level higher than the limit of the EU air quality directive. The smoke plume spreading over the area of Naples in this period was characterized by active (lidar) and passive (sun photometer) remote sensing as well as near-surface (optical particle counter) observational techniques. The measurements allowed us to follow both the PM variation at ground level and the vertical profile of fresh biomass burning aerosol as well as to analyze the optical and microphysical properties. The results evidenced the presence of a layer of fine mode aerosol with large mean values of optical depth (AOD > 0.25) and Ångstrom exponent (γ > 1.5) above the observational site. Moreover, the lidar ratio and aerosol linear depolarization obtained from the lidar observations were about 40 sr and 4%, respectively, consistent with the presence of biomass burning aerosol in the atmosphere.

Volcanic Emissions, Plume Dispersion, and Downwind Radiative Impacts Following Mount Etna Series of Eruptions of February 21–26, 2021

“…Details on this LiDAR system are reported by Boselli et al. (2021). Vertical profiles of the aerosol extinction coefficient and linear depolarization ratio are shown and discussed in this paper.…”

“…The station is equipped with a multiwavelength elastic/Raman LiDAR device able to detect elastic signals at 355, 532, and 1,064 nm, Raman N 2 echoes at 386 and 607 nm, and aerosol depolarization at 532 nm. Details on this LiDAR system are reported by Boselli et al (2021). Vertical profiles of the aerosol extinction coefficient and linear depolarization ratio are shown and discussed in this paper.…”

Aerosol Characterization with Long-Term AERONET Sun-Photometer Measurements in the Naples Mediterranean Area

“…The Napoli-CeSMA AERONET sun-photometer is located one kilometer from the Mediterranean Sea (40.83684° N, 14.30657° E, Elevation: 50.0 m). The measurement area (Figure 1) represents an ideal site for a long-term assessment of the various types of aerosol produced by different sources in the center of the Mediterranean basin, being influenced from marine aerosol of the near Mediterranean Sea [35,41], anthropogenic aerosol produced by the urban and industrial areas of Naples and the European region in the north [42], local and long-range transported biomass burning aerosol [43], and mineral dust transported from the Southern Sahara desert region [44,45]. Saharan dust transport events are very common in the Mediterranean basin [28].…”

“…Figure 3 reports the FIRMS map corresponding to 12 July 2017 when fires affected a very large area of the Vesuvius National Park and the smoke was driven by winds toward the city of Naples. The biomass burning aerosols were blown by wind toward the north-west direction, especially on 12 and 13 July when the wind speed reached values as high as 10 m/s [43].…”

Lidar Optical and Microphysical Characterization of Tropospheric and Stratospheric Fire Smoke Layers Due to Canadian Wildfires Passing over Naples (Italy)

“…In the same period, fire activity also struck the area close to Astroni Natural WWF Reserve. This extraordinary event was studied by means of vertically resolved lidar measurements that allowed for characterizing fresh biomass burning aerosol near the source [21].…”