ACROSS_LISA_RambForest_OPC_Sizedistr_PM1_1-Min_L2-station_processed

The aerosol particle number concentration in different size classes between 0.25 and 32 µm (optical equivalent diameter) was measured at the surface level by an optical particle counter (OPC) (GRIMM 1.109, Grimm Aerosol Technik GmbH & Co.) within the PEGASUS mobile platform located in Rambouillet, France – ACROSS project. The instrument was operated at 1.2 l min–1 through a certified PM1 inlet (Leckel GmbH) located approximately 2 m above the ground level. Data were acquired continously at 6 sec resolutions and averaged over 1-min. The time indicated in the datafile is the start time of the 1-min interval. Data acquired at ambient conditions were reported to Standard Temperature and Pressure conditions (STP, T=273.15K and P=1013.25 mbar). Meteorological data measured at the site (Denjean, 2023) were used as reference for ambient T and P. The average estimated error of 23% accounts for uncertainties due to Poisson statistics on total number of particles with optical diameter <1µm. Raw data were controlled manually to check periods when specific conditions prevented to do measurements or affected the quality of the measurements (power cut, disfunctioning). Data in correspondence of these periods are identified as -9999.999 and flagged with a “M” (missing). Valid data are reported with a “O” flag (operation). Detailed information on the dataset can be provided upon request to the author and the principal investigator.