Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece
COVID-19 is evolving into one of the worst pandemics in recent history, claiming a death toll of over 1.5 million as of December 2020. In an attempt to limit the expansion of the pandemic in its initial phase, nearly all countries imposed restriction measures, which resulted in an unprecedented redu...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-02-01
|
| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/12/2/231 |
| _version_ | 1827602019621273600 |
|---|---|
| author | Dimitris G. Kaskaoutis Georgios Grivas Eleni Liakakou Nikos Kalivitis Giorgos Kouvarakis Iasonas Stavroulas Panayiotis Kalkavouras Pavlos Zarmpas Umesh Chandra Dumka Evangelos Gerasopoulos Nikolaos Mihalopoulos |
| author_facet | Dimitris G. Kaskaoutis Georgios Grivas Eleni Liakakou Nikos Kalivitis Giorgos Kouvarakis Iasonas Stavroulas Panayiotis Kalkavouras Pavlos Zarmpas Umesh Chandra Dumka Evangelos Gerasopoulos Nikolaos Mihalopoulos |
| author_sort | Dimitris G. Kaskaoutis |
| collection | DOAJ |
| description | COVID-19 is evolving into one of the worst pandemics in recent history, claiming a death toll of over 1.5 million as of December 2020. In an attempt to limit the expansion of the pandemic in its initial phase, nearly all countries imposed restriction measures, which resulted in an unprecedented reduction of air pollution. This study aims to assess the impact of the lockdown effects due to COVID-19 on in situ measured aerosol properties, namely spectral-scattering (b<sub>sca</sub>) and absorption (b<sub>abs</sub>) coefficients, black carbon (BC) concentrations, single-scattering albedo (SSA), scattering and absorption Ångström exponents (SAE, AAE) in Athens, Greece. Moreover, a comparison is performed with the regional background site of Finokalia, Crete, for a better assessment of the urban impact on observed differences. The study examines pre-lockdown (1–22 March 2020), lockdown (23 March–3 May 2020) and post-lockdown (4–31 May 2020) periods, while the aerosol properties are also compared with a 3–4 year preceding period (2016/2017–2019). Comparison of meteorological parameters in Athens, between the lockdown period and respective days in previous years, showed only marginal variation, which is not deemed sufficient in order to justify the notable changes in aerosol concentrations and optical properties. The largest reduction during the lockdown period was observed for b<sub>abs</sub> compared to the pre-lockdown (−39%) and to the same period in previous years (−36%). This was intensified during the morning traffic hours (−60%), reflecting the large decrease in vehicular emissions. Furthermore, AAE increased during the lockdown period due to reduced emissions from fossil-fuel combustion, while a smaller (−21%) decrease was observed for b<sub>sca</sub> along with slight increases (6%) in SAE and SSA values, indicating that scattering aerosol properties were less affected by the decrease in vehicular emissions, as they are more dependent on regional sources and atmospheric processing. Nighttime BC emissions related to residential wood-burning were slightly increased during the lockdown period, with respect to previous-year means. On the contrary, aerosol and pollution changes during the lockdown period at Finokalia were low and highly sensitive to natural sources and processes. |
| first_indexed | 2024-03-09T05:09:41Z |
| format | Article |
| id | doaj.art-09c9a85440eb44f398c28d87b99398f4 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-09T05:09:41Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-09c9a85440eb44f398c28d87b99398f42023-12-03T12:50:57ZengMDPI AGAtmosphere2073-44332021-02-0112223110.3390/atmos12020231Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, GreeceDimitris G. Kaskaoutis0Georgios Grivas1Eleni Liakakou2Nikos Kalivitis3Giorgos Kouvarakis4Iasonas Stavroulas5Panayiotis Kalkavouras6Pavlos Zarmpas7Umesh Chandra Dumka8Evangelos Gerasopoulos9Nikolaos Mihalopoulos10Institute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceEnvironmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Heraklion, GreeceEnvironmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Heraklion, GreeceInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceEnvironmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Heraklion, GreeceAryabhatta Research Institute of Observational Sciences, Nainital 263001, IndiaInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceInstitute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, GreeceCOVID-19 is evolving into one of the worst pandemics in recent history, claiming a death toll of over 1.5 million as of December 2020. In an attempt to limit the expansion of the pandemic in its initial phase, nearly all countries imposed restriction measures, which resulted in an unprecedented reduction of air pollution. This study aims to assess the impact of the lockdown effects due to COVID-19 on in situ measured aerosol properties, namely spectral-scattering (b<sub>sca</sub>) and absorption (b<sub>abs</sub>) coefficients, black carbon (BC) concentrations, single-scattering albedo (SSA), scattering and absorption Ångström exponents (SAE, AAE) in Athens, Greece. Moreover, a comparison is performed with the regional background site of Finokalia, Crete, for a better assessment of the urban impact on observed differences. The study examines pre-lockdown (1–22 March 2020), lockdown (23 March–3 May 2020) and post-lockdown (4–31 May 2020) periods, while the aerosol properties are also compared with a 3–4 year preceding period (2016/2017–2019). Comparison of meteorological parameters in Athens, between the lockdown period and respective days in previous years, showed only marginal variation, which is not deemed sufficient in order to justify the notable changes in aerosol concentrations and optical properties. The largest reduction during the lockdown period was observed for b<sub>abs</sub> compared to the pre-lockdown (−39%) and to the same period in previous years (−36%). This was intensified during the morning traffic hours (−60%), reflecting the large decrease in vehicular emissions. Furthermore, AAE increased during the lockdown period due to reduced emissions from fossil-fuel combustion, while a smaller (−21%) decrease was observed for b<sub>sca</sub> along with slight increases (6%) in SAE and SSA values, indicating that scattering aerosol properties were less affected by the decrease in vehicular emissions, as they are more dependent on regional sources and atmospheric processing. Nighttime BC emissions related to residential wood-burning were slightly increased during the lockdown period, with respect to previous-year means. On the contrary, aerosol and pollution changes during the lockdown period at Finokalia were low and highly sensitive to natural sources and processes.https://www.mdpi.com/2073-4433/12/2/231COVID-19trafficaerosol scatteringabsorptionSSAGreece |
| spellingShingle | Dimitris G. Kaskaoutis Georgios Grivas Eleni Liakakou Nikos Kalivitis Giorgos Kouvarakis Iasonas Stavroulas Panayiotis Kalkavouras Pavlos Zarmpas Umesh Chandra Dumka Evangelos Gerasopoulos Nikolaos Mihalopoulos Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece Atmosphere COVID-19 traffic aerosol scattering absorption SSA Greece |
| title | Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece |
| title_full | Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece |
| title_fullStr | Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece |
| title_full_unstemmed | Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece |
| title_short | Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece |
| title_sort | assessment of the covid 19 lockdown effects on spectral aerosol scattering and absorption properties in athens greece |
| topic | COVID-19 traffic aerosol scattering absorption SSA Greece |
| url | https://www.mdpi.com/2073-4433/12/2/231 |
| work_keys_str_mv | AT dimitrisgkaskaoutis assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT georgiosgrivas assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT eleniliakakou assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT nikoskalivitis assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT giorgoskouvarakis assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT iasonasstavroulas assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT panayiotiskalkavouras assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT pavloszarmpas assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT umeshchandradumka assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT evangelosgerasopoulos assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece AT nikolaosmihalopoulos assessmentofthecovid19lockdowneffectsonspectralaerosolscatteringandabsorptionpropertiesinathensgreece |