Arctic lightning NO2 product (2021)

The dataset includes results from a combination of TROPOMI NO₂ measurements and GLD360 observations in the Arctic (<strong>June-August 2021</strong>). By analyzing consecutive TROPOMI NO₂ observations, we determine the lifetime and production efficiency of lightning NO₂. A detailed description of the methodology can be found in Zhang et al. (2023). <strong>Reference</strong> Zhang et al., <strong>Spaceborne observations of lightning NO₂ in the Arctic</strong>, <em>Environ. Sci. Technol.</em> <strong>Date files</strong> These NetCDF files are generated by S5P-LNO2 which depends on TROPOMI NO₂ data and GLD360 lightning data. Here is the variable table of the S5P-LNO2 NetCDF product: Varname Group Units Description time S5P days since &lt;yyyy-mm-dd&gt; time using proleptic gregorian calendar latitude S5P degrees_north pixel center latitude longitude S5P degrees_east pixel center longitude air_mass_factor_clear S5P 1 Air mass factor for the cloud-free part of the scene air_mass_factor_cloudy S5P 1 Air mass factor for the cloud-covered part of the scene air_mass_factor_stratosphere S5P 1 Stratospheric air mass factor air_mass_factor_total S5P 1 Total air mass factor air_mass_factor_troposphere S5P 1 Tropospheric air mass factor Apparent_scene_pressure S5P Pa Scene pressure from the cloud product assembled_lat_bounds S5P degrees_north assembled_latitude_bounds calculated by Satpy assembled_lon_bounds S5P degrees_east assembled_longitude_bounds calculated by Satpy Averaging_kernel S5P 1 Averaging kernel cloud_albedo_crb S5P 1 Cloud albedo in the cloud product cloud_fraction_crb_nitrogendioxide_window S5P 1 Cloud fraction at 440 nm for NO2 retrieval cloud_pressure_crb S5P Pa Cloud optical centroid pressure cloud_radiance_fraction_nitrogendioxide_window S5P 1 Cloud radiance fraction at 440 nm for NO2 retrieval Geolocation_flags S5P 1 Some flags (see ATBD) <strong>lightning_mask</strong> S5P 1 &lt;0: labeled lightning with fire; 0: no lightning; &gt;0: labeled lightning without fire nitrogendioxide_ghost_column S5P mol m-2 Ghost column NO2: modelled NO2 column below the cloud top <strong>nitrogendioxide_segmentation</strong> S5P 1 0: no high NO2; &gt;=1: labeled high NO2 nitrogendioxide_slant_column_density S5P mol m-2 Stratospheric vertical column of nitrogen dioxide, derived from the TM5-MP vertical profiles nitrogendioxide_stratospheric_column S5P mol m-2 Stratospheric vertical column of nitrogen dioxide, derived from the TM5-MP vertical profile nitrogendioxide_total_column S5P mol m-2 Total vertical column of nitrogen dioxide derived from the total slant column and TM5 profile in stratosphere and troposphere nitrogendioxide_tropospheric_column S5P mol m-2 Tropospheric vertical column of nitrogen dioxide processing_quality_flags S5P 1 Processing quality flags (See ATBD) qa_value S5P 1 Quality value scene_albedo S5P 1 Scene albedo in the cloud product snow_ice_flag S5P 1 Snow-ice mask (See ATBD) solar_azimuth_angle S5P degree clockwise from the North (East = 90, South = 180, West = 270) Solar azimuth angle at the ground pixel location on the reference ellipsoid. solar_zenith_angle S5P degree measured away from the vertical Solar zenith angle at the ground pixel location on the reference ellipsoid. surface_albedo_nitrogendioxide_window S5P 1 Surface albedo in the NO2 fit window surface_pressure S5P Pa Surface pressure time_utc S5P 1 Time of observation as ISO 8601 date-time string tm5_constant_a S5P Pa TM5 hybrid A coefficient at upper and lower interface levels tm5_constant_b S5P Pa TM5 hybrid B coefficient at upper and lower interface levels tm5_tropopause_layer_index S5P 1 TM5 layer index of the highest layer in the tropopause viewing_azimuth_angle S5P degree measured clockwise from the North (East = 90, South = 180, West = 270) Satellite azimuth angle at the ground pixel location on the reference ellipsoid. viewing_zenith_angle S5P degree measured away from the vertical Zenith angle of the satellite at the ground pixel location on the reference ellipsoid. cluster_label Lightning 1 Clustered lightning labeled by DBSCAN time Lightning minutes since longitude Lightning degrees_east Longitude of lightning latitude Lightning degrees_north Latitude of lightning delta Lightning minute The time difference between detected lightning and TROPOMI overpass time level Lightning hPa Pressure levels used for lightning NO2 air parcel longitude_pred Lightning degrees_east Longitude of lightning at different pressure levels predicted by ERA5 data latitude_pred Lightning degrees_north Latitude of lightning at different pressure levels predicted by ERA5 data lightning_label Lightning 1 Lightning label paired with lightning mask time Fire 1 longitude Fire degrees_north Longitude of fire latitude Fire degrees_north Longitude of fire type Fire 1 Fire type