Supplement to "Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean"

The dataset contains (O)VOC concentration data that were acquired with a hs-PTR-MS instrument at the Maido observatory at Reunion Island. It is a subset of a larger dataset that was acquired in the framework of the OCTAVE project.

A selection of the 2-year dataset recorded by the high-sensitivity quadrupole-based Proton Transfer
Reaction Mass spectrometry instrument (hs-PTR-MS, Ionicon Analytik GmbH, Austria) at the
Maïdo observatory (21.4°S, 55.1°E, 2150 m altitude) in the framework of the OCTAVE project is
provided here.

The hs-PTR-MS instrument was run in multiple ion detection mode using H3O+
precursor ions and a total cycle time of ~2.7 minutes. The data was combined to generate hourly
averages in order to lower both the limit of detection and the stochastic error on measurements.
Regular calibrations were performed twice a week. Intensive calibrations as a function of relative
humidity were done every two months. The systematic uncertainties are expected to be 5%
(corresponding to the stated accuracy of the calibration mixture) for compounds that are calibrated
in a direct manner. Calibration factors for formic acid and acetic acid were estimated using those of
acetaldehyde and acetone, respectively, and ion/molecule reaction kinetics and product ion
distributions. The systematic uncertainty for those carboxylic acids is estimated to be 50%.

The complete dataset will be submitted to the EBAS database in the framework of the ACTRIS (European Research Infrastructure for the observation of Aerosol, Clouds and Trace Gases) project.
The current selection is made to characterise biomass burning plumes arriving at the observatory
originating from burning events in southern Africa and Madagascar recorded in August 2018 and
August 2019.
It is the core dataset used in the referenced publication, and more details on this data can be found in this article.

Size: 3,3 MB