Long term satellite observations of tropospheric formaldehyde HCHO are essential to support air quality and chemistry-climate related studies from the regional to the global scale. Formaldehyde is an intermediate gas in almost all oxidation chains of non-methane volatile organic compounds (NMVOC), leading eventually to CO2. Non-Methane Volatile Organic Compounds (NMVOCs) are, together with NOx, CO and CH4, among the most important precursors of tropospheric O3. The major HCHO source in the remote atmosphere is CH4 oxidation. Over the continents, the oxidation of higher NMVOCs emitted from vegetation, fires, traffic and industrial sources results in important and localized enhancements of the HCHO levels. The seasonal and inter-annual variations of the formaldehyde distribution are principally related to temperature changes and fire events, but also to changes in anthropogenic activities. Its lifetime being of the order of a few hours, HCHO concentrations in the boundary layer can be directly related to the release of short-lived hydrocarbons, which mostly cannot be observed directly from space.
The first months of TROPOMI HCHO observations appear to be of excellent quality. The good signal-to-noise ratio of TROPOMI yields stunning images of HCHO. The global map below shows HCHO concentrations created with TROPOMI L2 data, from the period November 2017 through June 2018. Read more about TROPOMI HCHO via this link.
|Version number||Version Effective Orbit Number and Date||Summary of Changes|
|2.03.00||OFFL: orbit 22768, 2022-03-06
NRTI: orbit 22813, 2022-03-09
Current version; background correction improved
|2.02.01||OFFL: orbit 19258, 2021-07-01
NRTI: orbit 19308, 2021-07-05
|updated L1b, see PRF|
|2.01.04||OFFL: orbit 16213, 2020-11-29
NRTI: orbit 16259, 2020-12-02
USER DOCUMENTATION: ATBD, PUM, & README
Links to the Algorithm Theoretical Basis Document (ATBD) the Product User Manual (PUM), and the Product Readme File (PRF) are located on the right of this page under Documentation. This data product was released in October 2018 and is now available on the Copernicus Open Data Access Hub (see link on the right). A supporting PUM for a priori profile data used for HCHO is also available here. The interested user can download a tool developed in Python for working with the TROPOMI a priori profiles used for NO2, SO2, and HCHO (see download link here below).