HAS doctoral student Mostafa Javadian and his faculty advisor, HAS Associate Professor Ali Behrangi, have some exciting new research to share! Using NASA and European Space Agency satellite data and Google Earth Engine, Javadian has created an app to monitor the NO2 levels in large cities around the entire globe. Javadian provided a short description and a sample image from this study which is provided below.
Using satellites to monitor COVID-19 impact on large cities
The coronavirus (COVID-19) epidemic is first and foremost an issue of human health and safety. But as people have changed their everyday behaviors and patterns to contain or avoid the virus, there have been some subtle effects on the environment. NASA and European Space Agency (ESA) pollution monitoring satellites have detected significant decreases in nitrogen dioxide (NO2) over most big cities in the world. Nitrogen dioxide is produced from car engines, power plants and other industrial processes and is thought to exacerbate respiratory illnesses such as asthma. The data were collected by the Tropospheric Monitoring Instrument (TROPOMI) on ESA’s Sentinel-5 satellite.
The map below shows NO2 values across Tehran, Iran for March 1-13, 2019 (before the quarantine) and March 1-13, 2020 (during the quarantine). The results suggest that nitrogen dioxide (NO2) levels have dropped by 28% in Tehran from last year, after the coronavirus outbreak, most likely due to less traffic in Iran's busy capital.
For a better global investigation of NO2 before and after the coronavirus outbreak, we developed an online application using Google Earth Engine to compare the NO2 level for the entire globe between the last and current year. The app is averaging NO2 density for the week that has been selected by the user. For example, by selecting "2020-03-15" from the left panel and "2019-03-15" from the right panel and then zoom in to New York, the user can see the significant decrease in NO2 density in that city.
(UPDATED) Link: Javadian App or open with this link -- https://javadian.users.earthengine.app/view/no2-monitoring-after-covid-19-outbreak