Calculation of daily spatial mean NO2 data for 9 Functional Urban Areas (FUAs) in Greece, from Sentinel– 5p Satellite (TROPOMI)
The process has been developed by the Atmospheric Chemistry and Physics Group (APCG) of the Institute for Environmental Research and Sustainable Development (IERSD/NOA) within the H2020 SMURBS/ERA-PLANET project.
For further information please contact Dr. Evangelos Gerasopoulos (egera@noa.gr) and Anastasia Kakouri (nkakouri@noa.gr).
DISCLAIMERS
- Quality assurance values > 0.5 were used as flag for the pixel selection. This flagging adds the good quality retrievals over clouds and over scenes covered by snow/ice, while still filtering out errors and problematic retrievals. For the calculation of the FUA spatial means, if more than 30% of the NO2 data due to the quality assurance flag is missing, the mean is considered as missing value.
- Two key dates for COVID-19 measures should be considered. March 15th as the start of the first mitigation guides and March 23rd as the date of the general lockdown. For the calculation of percentage changes, we use the first date. Changes are calculated in relation to i) the average concentration measured since the beginning of the year, ii) the average concentrations during February.
- To evaluate the temporal variability of concentrations in association with the adopted “lockdown” measures, climatological and meteorological factors should also be taken into consideration.
NOTE: Different axis-scale is used for each FUA to optimize the visualization of variability. - The user assumes the entire risk related to its use of this data. APCG/NOA is providing this data "as is" and disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will APCG/NOA be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data.