Gases 2025, 5(1), 5; https://doi.org/10.3390/gases5010005 - 13 Feb 2025
Abstract
The central Mediterranean and nearby regions were affected by extreme wildfires during the summer of 2021. During the crisis, Türkiye, Greece, Italy, and other countries faced numerous challenges ranging from the near-complete destruction of landscapes to human losses. The crisis also resulted in
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The central Mediterranean and nearby regions were affected by extreme wildfires during the summer of 2021. During the crisis, Türkiye, Greece, Italy, and other countries faced numerous challenges ranging from the near-complete destruction of landscapes to human losses. The crisis also resulted in reduced air quality levels due to increased emissions of pollutants linked to biomass-burning processes. In the Mediterranean Basin, observation sites perform continuous measurements of chemical and meteorological parameters meant to track and evaluate greenhouse gas and pollutant emissions in the area. In the case of wildfires, CO (carbon monoxide) and formaldehyde (HCHO) are effective tracers of this phenomenon, and the integration of satellite data on tropospheric column densities with surface measurements can provide additional insights on the transport of air masses originating from wildfires. At the Lamezia Terme (code: LMT) World Meteorological Organization–Global Atmosphere Watch (WMO/GAW) observation site in Calabria, Southern Italy, a new multiparameter approach combining different methodologies has been used to further evaluate the effects of the 2021 wildfires on atmospheric measurements. A previous study focused on wildfires that affected the Aspromonte Massif area in Calabria; in this study, the integration of surface data, tropospheric columns, and backtrajectories has allowed pinpointing additional contributions from other southern Italian regions, as well as North Africa and Greece. CO data were available for both surface and column assessments, while continuous HCHO data at the site were only available through satellite. In order to correlate the observed peaks with wildfires, surface BC (black carbon) was also analyzed. The analysis, which focused on July and August 2021, has allowed the definition of three case studies, each highlighting distinct sources of emission in the Mediterranean; the case studies were further evaluated using HYSPLIT backtrajectories and CAMS products. The LMT site and its peculiar local wind patterns have been demonstrated to play a significant role in the detection of wildfire outputs in the context of the Mediterranean Basin. The findings of this study further stress the importance of assessing the effects of wildfire emissions over wide areas.
Full article
(This article belongs to the Special Issue Air Quality: Monitoring and Assessment)
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Figure 1
Figure 1
<p>(<b>A</b>) LMT’s location in the central Mediterranean Basin. (<b>B</b>) Modified EMODnet [<a href="#B80-gases-05-00005" class="html-bibr">80</a>] map showing LMT’s coordinates and location in the southern Italian region of Calabria.</p> Full article ">Figure 2
<p>Hourly averages of surface CO (<b>A</b>) and eBC (<b>B</b>) at LMT between July and August 2021. The cyan line shows a 36-h moving average.</p> Full article ">Figure 3
<p>Daily averaged tropospheric total column densities of CO and HCHO (<b>A</b>); surface concentrations of CO (<b>B</b>) and eBC (<b>C</b>) at Lamezia Terme station, both differentiated by wind corridor.</p> Full article ">Figure 4
<p>Daily cycles of surface CO (<b>A</b>) and eBC (<b>B</b>), differentiated by wind sector.</p> Full article ">Figure 4 Cont.
<p>Daily cycles of surface CO (<b>A</b>) and eBC (<b>B</b>), differentiated by wind sector.</p> Full article ">Figure 5
<p>Direct comparison between daily satellite total column densities of CO and HCHO and the hourly concentrations of surface CO (blue diamonds) observed at the time of satellite passage, 14:00 UTC.</p> Full article ">Figure 6
<p>FIRMS data on fires affecting the central Mediterranean area between 8 July and 14 July 2021. Light colors indicate fires lasting for 5+ days, thus contributing to prolonged emissions. Italian regions are marked in italics, while other countries are marked in bold. Malta, Spain, and France, as well as several Italian regions, have been omitted to improve visualization.</p> Full article ">Figure 7
<p>CO and HCHO vertical column data referring to 10–12 July, which is the first case study assessed in this research (CS1). CO column data on 12 July and HCHO column data on 9 and 11 July were not available.</p> Full article ">Figure 7 Cont.
<p>CO and HCHO vertical column data referring to 10–12 July, which is the first case study assessed in this research (CS1). CO column data on 12 July and HCHO column data on 9 and 11 July were not available.</p> Full article ">Figure 8
<p>HYSPLIT backtrajectory computed from LMT’s coordinates, showing well-defined paths leading to the Italian region of Sardinia.</p> Full article ">Figure 9
<p>CAMS products showing the diffusion of CO on 10 July (CS1).</p> Full article ">Figure 9 Cont.
<p>CAMS products showing the diffusion of CO on 10 July (CS1).</p> Full article ">Figure 10
<p>FIRMS data on fires affecting the central Mediterranean area between 28 July and 3 August 2021. Light colors indicate fires lasting for 5+ days that contribute to prolonged emissions. Country names are in bold. Malta, Spain, and France have been omitted to improve visualization.</p> Full article ">Figure 11
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 11 Cont.
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 11 Cont.
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 12
<p>HYSPLIT backtrajectory of CS2 indicating Algeria as a probable source.</p> Full article ">Figure 13
<p>CAMS products showing the diffusion of CO from 29 to 30 July (CS2).</p> Full article ">Figure 13 Cont.
<p>CAMS products showing the diffusion of CO from 29 to 30 July (CS2).</p> Full article ">Figure 14
<p>FIRMS map showing areas affected by wildfires between 31 July and 6 August, with lighter colors indicating wildfires lasting for 5+ days. Balkan countries other than Greece and Cyprus have been omitted from labeling to improve visualization.</p> Full article ">Figure 15
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 15 Cont.
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 15 Cont.
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 16
<p>HYSPLIT computed backtrajectories, set at LMT’s coordinates, for CS3.</p> Full article ">Figure 17
<p>CAMS products showing the diffusion of CO on 4 August (CS3).</p> Full article ">Figure 17 Cont.
<p>CAMS products showing the diffusion of CO on 4 August (CS3).</p> Full article ">
<p>(<b>A</b>) LMT’s location in the central Mediterranean Basin. (<b>B</b>) Modified EMODnet [<a href="#B80-gases-05-00005" class="html-bibr">80</a>] map showing LMT’s coordinates and location in the southern Italian region of Calabria.</p> Full article ">Figure 2
<p>Hourly averages of surface CO (<b>A</b>) and eBC (<b>B</b>) at LMT between July and August 2021. The cyan line shows a 36-h moving average.</p> Full article ">Figure 3
<p>Daily averaged tropospheric total column densities of CO and HCHO (<b>A</b>); surface concentrations of CO (<b>B</b>) and eBC (<b>C</b>) at Lamezia Terme station, both differentiated by wind corridor.</p> Full article ">Figure 4
<p>Daily cycles of surface CO (<b>A</b>) and eBC (<b>B</b>), differentiated by wind sector.</p> Full article ">Figure 4 Cont.
<p>Daily cycles of surface CO (<b>A</b>) and eBC (<b>B</b>), differentiated by wind sector.</p> Full article ">Figure 5
<p>Direct comparison between daily satellite total column densities of CO and HCHO and the hourly concentrations of surface CO (blue diamonds) observed at the time of satellite passage, 14:00 UTC.</p> Full article ">Figure 6
<p>FIRMS data on fires affecting the central Mediterranean area between 8 July and 14 July 2021. Light colors indicate fires lasting for 5+ days, thus contributing to prolonged emissions. Italian regions are marked in italics, while other countries are marked in bold. Malta, Spain, and France, as well as several Italian regions, have been omitted to improve visualization.</p> Full article ">Figure 7
<p>CO and HCHO vertical column data referring to 10–12 July, which is the first case study assessed in this research (CS1). CO column data on 12 July and HCHO column data on 9 and 11 July were not available.</p> Full article ">Figure 7 Cont.
<p>CO and HCHO vertical column data referring to 10–12 July, which is the first case study assessed in this research (CS1). CO column data on 12 July and HCHO column data on 9 and 11 July were not available.</p> Full article ">Figure 8
<p>HYSPLIT backtrajectory computed from LMT’s coordinates, showing well-defined paths leading to the Italian region of Sardinia.</p> Full article ">Figure 9
<p>CAMS products showing the diffusion of CO on 10 July (CS1).</p> Full article ">Figure 9 Cont.
<p>CAMS products showing the diffusion of CO on 10 July (CS1).</p> Full article ">Figure 10
<p>FIRMS data on fires affecting the central Mediterranean area between 28 July and 3 August 2021. Light colors indicate fires lasting for 5+ days that contribute to prolonged emissions. Country names are in bold. Malta, Spain, and France have been omitted to improve visualization.</p> Full article ">Figure 11
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 11 Cont.
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 11 Cont.
<p>Tropospheric columns of CO and HCHO referred to CS2 (specifically, 29–31 July), showing a northern African source of the peaks observed at LMT.</p> Full article ">Figure 12
<p>HYSPLIT backtrajectory of CS2 indicating Algeria as a probable source.</p> Full article ">Figure 13
<p>CAMS products showing the diffusion of CO from 29 to 30 July (CS2).</p> Full article ">Figure 13 Cont.
<p>CAMS products showing the diffusion of CO from 29 to 30 July (CS2).</p> Full article ">Figure 14
<p>FIRMS map showing areas affected by wildfires between 31 July and 6 August, with lighter colors indicating wildfires lasting for 5+ days. Balkan countries other than Greece and Cyprus have been omitted from labeling to improve visualization.</p> Full article ">Figure 15
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 15 Cont.
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 15 Cont.
<p>Vertical columns of the case study 3 (CS3), referring to the period between 2 August and 4 August. Column density data show surges in emissions from Greece.</p> Full article ">Figure 16
<p>HYSPLIT computed backtrajectories, set at LMT’s coordinates, for CS3.</p> Full article ">Figure 17
<p>CAMS products showing the diffusion of CO on 4 August (CS3).</p> Full article ">Figure 17 Cont.
<p>CAMS products showing the diffusion of CO on 4 August (CS3).</p> Full article ">
