FTIR formic acid (HCOOH) total columns and low vertical resolution profile data at Porto Velho (Brazil). Details on the FTIR retrieval technique can be found in a paper describing our Reunion Island data (https://doi.org/10.5194/acp-12-10367-2012). The retrieval parameters used in the present HCOOH time-series at Porto Velho are following this latter study. Data users are kindly invited to collaborate to ensure a proper use of the FTIR data (e.g. appropriate use of the averaging kernels). The guidelines in the GEOMS documentation should be used to select the latest version of a data file in case files have overlapping dates.