European cities have seen a dramatic drop in Nitrogen Dioxide (No2) levels as a result of the lockdown – the simple act of reducing transport has transformed the environment. The same impact has been seen in China as the lockdown came into force. In China, a dramatic change in NO2 levels is also seen each year due to the Lunar New Year holiday.
The images below show how France and Spain’s air pollution levels have changed between March 2019 and March 2020.
Spain -Before and After Lockdown (March 2019 and March 2020)
Essen -Before and After Lockdown (March 2019 and March 2020)
The reason that NO2 is monitored so much is that it is associated with causing respiratory issues, as it impacts the lungs – this is especially acute in children, the elderly and those with asthma.
Two of the satellite systems used for tracking NO2 are:
- Tropospheric Monitoring Instrument (TROPOMI) on ESA’s Sentinel-5 satellite.
- Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite