- Analysed stations:
CT-1 (latitude: 44.18 , longitude: 28.64 , altitude: 45.00) | CT-4 (latitude: 43.82 , longitude: 28.58 , altitude: 16.00) |
- Nitrogen Dioxide (NO2) Analysis:
Contrary to our expectations, the NO2 emissions were generally higher in 2020 than in 2019, so the restrictions did not have such a big impact to reduce air pollution. However, since November 27th until the end of the year, we can observe an important decrease of the emissions compared to the rest of the year 2020, the values being also slightly lower than those in 2019. That is exactly the period in which the big city Constanta (where station CT-1 is located) was quarantined due to the many COVID-19 cases in the area.

- Carbon Monoxide (CO) Analysis:
There is a small difference between the emissions of CO from 2019 and the ones from 2020. Still, we can see that in March, at the beginning of the quarantine, there has been a substantial decrease of carbon monoxide. This proves that, although people stopped circulating, there are significantly more important sources of pollution in Constanta, such as naval accidents or the activities which take place in order to extract petroleum.

- Sulfur Dioxide (SO2) Analysis:
Unfortunately, the CT-1 station offers data both from 2019 and 2020 only for the months August and September, so we cannot make any observations on the state of emergency or on the other quarantine in Constanta (December 2020). However, the chart shows an amazing decrease of the SO2 emissions, the quantities of SO2 in 2020 being almost throughout the whole analysed period at half their values in 2019. This decrease is very important, considering that, even though in August and September there were not so many circulation restrictions, people in Constanta County realized the extent of the pandemic and limited circulation.

- Conclusion:
All in all, we conclude that the pandemic and imposed restrictions had a huge impact on the SO2 emissions (which decreased substantially), but did not make much difference in the case of CO emissions (which were already mostly very low). As for the NO2, the emissions decreased only in the quarantine period in December, but not during the state of emergency from March 16 to May 14.