Aerosol optical depth and solar irradiance data acquired in the frame of the JRP project MAPP, Metrology for Aerosol Optical Properties 19ENV04 with the Precision FilterRadiometer PFR-98-N-001. Monitoring period at Davos, 2021 -2022 Rome Campaign – Sep.2021 Izaña Campaign -Sep.2022 for the dataset of version 1.0 the calibration of the PFR is against the PFR-Triad has been used. For the SI-traceable AOD retrieval the PTB (Physikalisch-Technische Bundesanstalt, Braunschweig, Germany) calibration (Kouremeti, Nevas et al. 2022) has been used in combination with QASUMEFTS (Gröbner, Kröger et al. 2017) for 368 nm and 412 nm, and TSIS-1 (Coddington, Richard et al. 2021) for 501 nm and 862 nm. Calibration Record The calibration record given as Top-of-Atmosphere PFR signal (V0) and the expanded combined uncertainty of V0 (U) are given in the following table in Volts . PFR-TRIAD (2021) PTB Langley Izaña V0 (V) U (V) V0 (V) U (V) V0 (V) U (V) 862nm 3.380 0.017 3.3602 0.006 3.376 0.003 501nm 3.717 0.010 3.7326 0.006 3.712 0.004 412nm 3.503 0.010 3.5368 0.010 3.493 0.005 368nm 4.011 0.012 4.0438 0.026 4.006 0.007 Data description The data are daily files in matlab table format (table name PFR) The table contains 5 variables: 'Station' , 'Instrument' , 'Date' , 'Data' , 'MetaData_Flags' The variables of each sub-table and theirs units can be seen using e.g. the following : PFR.Data{1}.Properties.VariableNames, PFR.Data{1}.Properties.VariableUnits The signal, irradiance and atmospheric transmittance have been corrected for the Sun-Earth distance and are given at 1AU. Measurements, calibration and aanlysis performed by NK References Coddington, O. M., E. C. Richard, D. Harber, P. Pilewskie, T. N. Woods, K. Chance, X. Liu and K. Sun (2021). "The TSIS-1 Hybrid Solar Reference Spectrum." Geophysical Research Letters 48(12): e2020GL091709. Gröbner, J., I. Kröger, L. Egli, G. Hülsen, S. Riechelmann and P. Sperfeld (2017). "The high-resolution extraterrestrial solar spectrum (QASUMEFTS) determined from ground-based solar irradiance measurements." Atmos. Meas. Tech. 10(9): 3375-3383. Kouremeti, N., S. Nevas, S. Kazadzis, J. Gröbner, P. Schneider and K. M. Schwind (2022). "SI-traceable solar irradiance measurements for aerosol optical depth retrieval." Metrologia 59(4): 044001. Acknowledgments This data was obtained within the joint research project EMPIR 19ENV04 MAPP “Metrology for aerosol optical properties” which has been supported by the European Metrology Program for Innovation and Research (EMPIR) . The EMPIR is jointly funded by the EMPIR participating countries within EURAMET and the European Union.

{"references": ["Kouremeti, N., Nevas, S., Kazadzis, S., Gr\u00f6bner, J., Schneider, P., & Schwind, K. M. (2022). SI-traceable solar irradiance measurements for aerosol optical depth retrieval. Metrologia, 59(4), 044001. https://dx.doi.org/10.1088/1681-7575/ac6cbb"]}