Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations

Abstract We studied the impact of COVID-19 (coronavirus disease 2019) lockdown on the air quality over the Atlanta area using satellite and ground-based observations, meteorological reanalysis data and traffic information. Unlike other cities, we found the air quality has improved slightly over the...

Full description

Saved in:
Bibliographic Details
Main Authors: Guanyu Huang, Reyla Ponder, Amber Bond, Hailey Brim, Akua Temeng, Aaron R. Naeger, Lei Zhu
Format: Article
Language:English
Published: Springer 2021-09-01
Series:Aerosol and Air Quality Research
Subjects:
Online Access:https://doi.org/10.4209/aaqr.210153
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1823862886647201792
author Guanyu Huang
Reyla Ponder
Amber Bond
Hailey Brim
Akua Temeng
Aaron R. Naeger
Lei Zhu
author_facet Guanyu Huang
Reyla Ponder
Amber Bond
Hailey Brim
Akua Temeng
Aaron R. Naeger
Lei Zhu
author_sort Guanyu Huang
collection DOAJ
description Abstract We studied the impact of COVID-19 (coronavirus disease 2019) lockdown on the air quality over the Atlanta area using satellite and ground-based observations, meteorological reanalysis data and traffic information. Unlike other cities, we found the air quality has improved slightly over the Atlanta area during the 2020 COVID-19 lockdown period (March 14–April 30, 2020), compared to the analogous period of 2019 (March 14–April 30, 2019). Ground NO2 concentrations have decreased slightly 10.8% and 8.2% over the near-road (NR) and urban ambient (UA) stations, respectively. Tropospheric NO2 columns have reduced 13%–49% over the Atlanta area from space-borne observations of TROPOspheric Monitoring Instrument (TROPOMI). Ground ozone and PM2.5 have decreased 15.7% and ~5%, respectively. This slight air quality improvement is primarily caused by the reduced human activities, as COVID-19 lockdowns have reduced ~50% human activities, measured by traffic volume. Higher wind speed and precipitations also make the meteorological conditions favorable to this slight air quality improvement. We have not found a significant improvement in air quality over Atlanta amid the lockdown when human activities have reduced ~50%. Further studies are needed to understand the impacts of reduced human activities on atmospheric chemistry. We also found TROPOMI and ground measurements have disagreements on NO2 reductions, as collocated TROPOMI observations revealed ~23% and ~21% reductions of tropospheric NO2 columns over NR and UA stations, respectively. Several factors may explain this disagreement: First, tropospheric NO2 columns and ground NO2 concentrations are not necessarily the same, although they are highly correlated in the afternoon; Second, meteorological conditions may have different impacts on TROPMI and ground measurements. Third, TROPOMI may underestimate tropospheric NO2 due to uncertainties from air mass factors. Fourth, the uncertainties of chemiluminescence NO2 measurements used by ground stations. Consequently, studies using space-borne tropospheric NO2 column and ground NO2 measurements should take these factors into account.
format Article
id doaj-art-4db1c62bcc7d4bcbb981e8612c9835f5
institution Kabale University
issn 1680-8584
2071-1409
language English
publishDate 2021-09-01
publisher Springer
record_format Article
series Aerosol and Air Quality Research
spelling doaj-art-4db1c62bcc7d4bcbb981e8612c9835f52025-02-09T12:20:27ZengSpringerAerosol and Air Quality Research1680-85842071-14092021-09-01211111410.4209/aaqr.210153Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite ObservationsGuanyu Huang0Reyla Ponder1Amber Bond2Hailey Brim3Akua Temeng4Aaron R. Naeger5Lei Zhu6Environmental and Health Sciences Program, Spelman CollegeDepartment of Mathematics, Spelman CollegeEnvironmental and Health Sciences Program, Spelman CollegeEnvironmental and Health Sciences Program, Spelman CollegeDepartment of Chemistry and Biochemistry, Spelman CollegeEarth System Science Center, University of Alabama in HuntsvilleSchool of Environmental Science and Engineering, Southern University of Science and TechnologyAbstract We studied the impact of COVID-19 (coronavirus disease 2019) lockdown on the air quality over the Atlanta area using satellite and ground-based observations, meteorological reanalysis data and traffic information. Unlike other cities, we found the air quality has improved slightly over the Atlanta area during the 2020 COVID-19 lockdown period (March 14–April 30, 2020), compared to the analogous period of 2019 (March 14–April 30, 2019). Ground NO2 concentrations have decreased slightly 10.8% and 8.2% over the near-road (NR) and urban ambient (UA) stations, respectively. Tropospheric NO2 columns have reduced 13%–49% over the Atlanta area from space-borne observations of TROPOspheric Monitoring Instrument (TROPOMI). Ground ozone and PM2.5 have decreased 15.7% and ~5%, respectively. This slight air quality improvement is primarily caused by the reduced human activities, as COVID-19 lockdowns have reduced ~50% human activities, measured by traffic volume. Higher wind speed and precipitations also make the meteorological conditions favorable to this slight air quality improvement. We have not found a significant improvement in air quality over Atlanta amid the lockdown when human activities have reduced ~50%. Further studies are needed to understand the impacts of reduced human activities on atmospheric chemistry. We also found TROPOMI and ground measurements have disagreements on NO2 reductions, as collocated TROPOMI observations revealed ~23% and ~21% reductions of tropospheric NO2 columns over NR and UA stations, respectively. Several factors may explain this disagreement: First, tropospheric NO2 columns and ground NO2 concentrations are not necessarily the same, although they are highly correlated in the afternoon; Second, meteorological conditions may have different impacts on TROPMI and ground measurements. Third, TROPOMI may underestimate tropospheric NO2 due to uncertainties from air mass factors. Fourth, the uncertainties of chemiluminescence NO2 measurements used by ground stations. Consequently, studies using space-borne tropospheric NO2 column and ground NO2 measurements should take these factors into account.https://doi.org/10.4209/aaqr.210153COVID-19Air qualityTROPOMINO2
spellingShingle Guanyu Huang
Reyla Ponder
Amber Bond
Hailey Brim
Akua Temeng
Aaron R. Naeger
Lei Zhu
Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
Aerosol and Air Quality Research
COVID-19
Air quality
TROPOMI
NO2
title Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
title_full Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
title_fullStr Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
title_full_unstemmed Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
title_short Unexpected Impact of COVID-19 Lockdown on the Air Quality in the Metro Atlanta, USA Using Ground-based and Satellite Observations
title_sort unexpected impact of covid 19 lockdown on the air quality in the metro atlanta usa using ground based and satellite observations
topic COVID-19
Air quality
TROPOMI
NO2
url https://doi.org/10.4209/aaqr.210153
work_keys_str_mv AT guanyuhuang unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT reylaponder unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT amberbond unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT haileybrim unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT akuatemeng unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT aaronrnaeger unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations
AT leizhu unexpectedimpactofcovid19lockdownontheairqualityinthemetroatlantausausinggroundbasedandsatelliteobservations