TROPOMI NO2 data version overview

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Tropospheric NO2

 

Note: the vertical dashed line marks a change in the along-track ground pixel size; this change did not lead to a change in the version number.

The TROPOMI NO2 data processor occasionally undergoes version updates, shown above as vN.M.x (where the last digit is for minor bug fixes only). The collection number (left most numbers) is currently linked to the version of the level-1b (ir)radiance spectra.

The initial operational processing started in May 2018 and constitutes versions v1.M.x, followed by v2.2.0 after updates of the level-1b data.

To harmonise the NO2 data, there was an intermediate reprocessing on the PAL system with version v2.3.1, up to the operational processing of that version. This dataset was published in December 2021, but is no longer available.

After further updates of the level-1b data and the NO2 processor, the current version is v2.4.0 -- this version is used for a full mission reprocessing up to the operational switch to v2.4.0, which replaces all previous versions.

Version v2.5.0 implements a small bug fix in the OFFL code. The change only affects the qa_value field in the datafiles over snow or ice covered regions; the update makes OFFL consistent with NRTI & RPRO v2.4.0 and the ATBD. A recipe to update OFFL v2.4.0 to v2.5.0 is given below.

For NO2 version v2.6.0 is exactly the same as v2.5.0.

collection version type start date
start orbit
end date
end orbit
dataset DOI
Obsolete versions:
01 v1.M.x OFFL
RPRO
30 April 2018
02818
01 July 2021
19257
10.5270/S5P-s4ljg54
02 v2.2.0 OFFL 01 July 2021
19258
14 Nov. 2021
21187
10.5270/S5P-9bnp8q8
v2.3.1 OFFL 14 Nov. 2021
21188
17 July 2022
24654
10.5270/S5P-9bnp8q8
PAL v2.3.1 PAL_ 01 May 2018
02832
14 Nov. 2021
21187
N/A
Versions to be used:
03 v2.4.0 RPRO 01 May 2018
02832
25 July 2022
24779
10.5270/S5P-9bnp8q8
OFFL 17 July 2022
24655
12 March 2023
28030
10.5270/S5P-9bnp8q8
The recommendation is to use the RPRO data up to the end
and only then switch to the OFFL data, so as to avoid spin-up
issues at the beginning of the OFFL data stream.
v2.5.0 OFFL 12 March 2023
28031
26 Nov. 2023
31704
10.5270/S5P-9bnp8q8
v2.6.0 OFFL 26 Nov. 2023
31705
TBD 10.5270/S5P-9bnp8q8

Examples of names of NO2 orbits:

   S5P_RPRO_L2__NO2____20180901T013259_20180901T031627_04578_01_010202_20190220T132149.nc
   S5P_PAL__L2__NO2____20180901T013358_20180901T031528_04578_01_020301_20211108T224129.nc
   S5P_OFFL_L2__NO2____20210901T004236_20210901T022405_20127_02_020200_20210902T174110.nc
   S5P_RPRO_L2__NO2____20220725T170921_20220725T185050_24776_03_020400_20230203T050713.nc
   S5P_OFFL_L2__NO2____20220821T220529_20220821T234658_25162_03_020400_20220825T083000.nc
       type            start_date      end_date        orbit CN vers.  production_date
where:

 

Recipe to update OFFL v2.4.0 to v2.5.0

Full quote from the Product ReadMe File regarding this update reads:
The version 02.05.00 NO2 product implements a small bug fix in the OFFL code. The change only affects the qa_value field in the datafiles, and only over snow or ice covered regions. In the corrected OFFL version there are more pixels that receive a qa_value > 0.75, in case the scene pressure over snow/ice matches the surface pressure to within 4% (was 2% in previous versions). The OFFL 02.04.00 code, operational since 17 July 2022, did not receive this latest change. The update makes OFFL consistent with NRTI, RPRO v02.04.00 and the ATBD.
The data user can adjust the qa_value of OFFL v2.4.0 by following this recipe:
    if ( 0.50 < qa_value_v240 < 0.75 ) then
      if ( 80 < snow_ice_flag < 104 ) then
        if ( 0.96 <= apparent_scene_pressure / surface_pressure <= 0.98 ) then
          qa_value_v250 = qa_value_v240 * 0.88 / 0.73
where 0.88 (0.73) is the qa_value multiplication factor for cases where the ratio between the scene and surface pressure is >0.96 (<0.96) in the bug-fixed data version -- in the OFFL v2.4.0 the limit was incorrectly set at 0.98.

 

TROPOMI NO2 data version documentation

 

Download of TROPOMI NO2 data

 


last modified: 21 May 2024
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