Tropomi provides several clouds data productes:

Cloud

This page shows the most recent validation reports.

Most recent contributions
First comparison results for the S5P CH4 product based on correlative reference measurements acquired by FTIR instruments contributing to NDACC and TCCON networks.
This VDAF web article gives further details on the first comparison results presented in the CH4 product readme file for the methane data product release (see http://www.tropomi.eu/data-products/methane). The main conclusion is that the product quality of this initial L2 CH4 dataset complies with the S5P mission requirements.
ROCVR Reports
Quarterly Validation Report of the Copernicus Sentinel-5 Precursor Operational Data Products #06:Apil 2018 - February 2020
Quarterly Validation Report of the Copernicus Sentinel-5 Precursor Operational Data Products #05: April 2018 – November 2019
Quarterly Validation Report of the Sentinel-5 Precursor Operational Data Products #04: April 2018 – August 2019
Quarterly Validation Report of the Sentinel-5 Precursor Operational Data Products #03: July 2018 – May 2019