Daily surface concentration of fire related PM2.5 for 2003-2025, modelled by SILAM CTM when using the MODIS satellite data for the fire radiative power

Description

Methods

We use the fire radiative power data of MODIS instrument onboard of Aqua and Terra satellite to estimate globally the fire radiative power (FRP) from wildfires for years 2003-2025. The FRP is converted to fire related fine particles (PM2.5) using calibrated emissions factors and diurnal profile, together with dynamical emission heights. In the current version of the dataset a full re-calibration of the emission factors was completed since, in addition to primary PM, the fire source now includes also the formation of the secondary organic aerosols (SOA). The re-calibration was done using both the aerosol optical depth measurements and the surface measurement of PM2.5. The inclusion of SOA resulted much higher PM2.5 concentrations, especially further from the fires.

The dispersion of the fire related PM is followed by using System for Integrated modeLling of Atmospheric coMposition (SILAM) chemistry transport model version 6.1 (http://silam.fmi.fi, open-source code http://github.com/fmidev/silam-model). The global scale simulations have a resolution of 0.2x0.2 degrees with 29 model levels reaching up to 10.5 Pascals (~64 km). The lowest layer top is at ~31 m. The European scale grid has a horizontal resolution of 0.1x0.1 degrees and the boundaries come from the global results calculated at a resolution of 0.5x0.5 degrees, top boundary being at ~16 km. Total column is extracted from the global run performed at a resolution of 0.5 degrees. All simulations have time resolution of one hour from which the daily averaged surface concentration and the total column are extracted to the this data-set. Both the global and European scale simulations use the ERA5 meteorology as a drive.

Technical info

TechnicalInfo: The dataset consists of three subsets: 1) NetCDF file europePM25fire01deg-MODIS-2003to2025DayMean.nc4 contains the daily averaged fire related PM2.5 surface concentration in 0.1 degree resolution in European region, defined by lon = W25...E45, and lat = N30...N72. 2) NetCDF files globPM25fire02deg-MODIS-YEARDayMean.nc4, where YEAR=2003,...,2025, contain the global daily averaged fire related PM2.5 surface concentration in 0.2 degree resolution. 3) NetCDF file globPM25fireTotCol05deg-MODIS-2003to2025DayMean.nc4 contains the global daily averaged total column of fire related PM2.5 in 0.5 degree resolution. Compared to the previous version of the dataset [ Dated March 11, 2025 with DOI: 10.57707/fmi-b2share.9bf837f1067342f38640e66c3acd41c6 ] the current version of the dataset includes the data for the year 2025, but most importantly the full period 2003-2025 is re-calculated to include also the secondary organic aerosols (SOA) from fires. Therefore, the total PM2.5 concentrations are 2...3 times larger than in the previous datasets. The data is trimmed, such that the relative precision is 2 digits. Also, note that the mass unit is changed from kg to ug, such that the surface concentrations are now in units of ug/m3, and total column in unit of ug/m2.