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OMI NO2 Time-Series Readme Document
The tropospheric NO2 vertical column density (VCD) time-series are calculated using the Version 4.0 Aura Ozone Monitoring Instrument (OMI) Nitrogen Dioxide (NO2) Standard Product (OMNO2) available at https://disc.gsfc.nasa.gov/datasets/OMNO2_003/summary. Only high quality ( VCD Quality Flags equal to 0 ) and cloud screened (Effective Cloud Fraction < 30% ) data were included in statistics. Additionally OMI row 46 was omitted due to possible row anomaly effects. The statistics are calculated for a 1x1 degree grid box surrounding each city over a 15 day period. Additional information on the time-series calculation can be found here: https://so2.gsfc.nasa.gov/no2/FAQs.htm
Contact Info: Zachary Fasnacht (zachary.fasnacht AT ssaihq.com); Nickolay Krotkov (nickolay.a.krotkov AT nasa.gov); Lok Lamsal (lok.lamsal AT nasa.gov)
The fields in the CSV files are:
Date(yyyy-mm-dd): Center date of 15 day window
City: Name of city
Country: Name of country for given city
LonCenter: Center longitude for city
LatCenter: Center latitude for city
BoundingCoordinates: Bounding Longitude and Latitude +/- 0.5 degrees around city center ([lon_min lat_min lon_max lat_max])
Median: Median NO2 value for 15 day window
Q1: 25th percentile of NO2 for 15 day window
Q3: 75th percentile of NO2 for 15 day window
Mean: Mean NO2 value for 15 day period
Baseline_Median: Median NO2 value for 15 day window for baseline period
Baseline_Q1: 25th percentile of NO2 for 15 day window for baseline period
Baseline_Q3: 75th percentile of NO2 for 15 day window for baseline period
Baseline_Mean: Mean NO2 value for 15 day period for baseline period
NumGoodSamples: Number of good quality OMI samples for the 15 day window
NumTotalSamples: Number of OMI samples in the grid box for the 15 day window, including bad data which is screened out for statistics
Baseline period is 2015-2019
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