Comparing Tropospheric NO2 Retrievals from OMI and TROPOMI during the COVID-19 Lockdowns
Abstract
The decreases in transportation use and power production during the COVID-19 lockdowns significantly reduced regional emissions of nitrogen dioxide (NO2) into the atmosphere. Since 2004, the Ozone Monitoring Instrument (OMI) UV-VIS spectrometer onboard the NASA EOS Aura satellite has been making measurements of ozone and other trace gases including NO2. In response to COVID-19, the NASA OMI team has developed a monitoring website to track changes in NO2 globally (OMI NO2 Monitoring Website ) using OMI tropospheric NO2 data. We highlight and examine these analyses including timeseries and maps of NO2 during the COVID-19 period in 2020 comparing these to baseline NO2 data from 2015-2019. In 2017, the European Space Agency (ESA) launched the Tropospheric Monitoring Instrument (TROPOMI) instrument on the Sentinel-5 Precursor (S5P). TROPOMI provides similar trace gas measurements but at a much higher spatial resolution. We compare NO2 measurements from the OMI and TROPOMI instruments during the COVID-19 period. In addition to the standard ESA NO2 product, we also present our modified TROPOMI NO2 retrievals using a similar algorithm to NASA's V4 OMI NO2 Standard Product. The main differences between the NASA and ESA TROPOMI NO2 algorithms are in calculation of the Air-Mass Factors (AMF), including the implementation of a dynamic geometry dependent surface reflectivity (GLER), improvements to cloud and snow AMF corrections, and high resolution (0.25o x 0.25o ) a-priori NO2 profiles from NASA's Global Modeling Initiative (GMI) model replay runs. The decreases in NO2 emissions due to COVID-19 lockdowns provide an excellent opportunity to compare NO2 data from OMI and TROPOMI, highlight the importance of the long-term satellite NO2 record from OMI, and demonstrate the benefit of higher resolution data from TROPOMI.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA005.0003F
- Keywords:
-
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES;
- 0240 Public health;
- GEOHEALTH;
- 1640 Remote sensing;
- GLOBAL CHANGE;
- 4337 Remote sensing and disasters;
- NATURAL HAZARDS