These data are a part of Multi-Decadal Sulfur Dioxide (SO2) Climatology from Satellite Instruments (MEaSUREs-12-0022 project). Version 2 of the global catalogue of emissions from large SO2 point sources combines data from the Ozone Monitoring Instrument (OMI) on NASA's EOS Aura spacecraft, the Ozone Mapping and Profiler Suite (OMPS) on the NASA-NOAA Suomi National Polar-orbiting Partnership (SNPP), and the TROPOspheric Monitoring Instrument (TROPOMI) on the ESA/Copernicus Sentinel-5 Precursor (S-5P) spacecraft.The catalogue MSAQSO2L4 file contains the site coordinates, source type, country, source name, annual SO2 emissions, annual emission uncertainties, and the number of satellite pixels in the fitting area for three satellite instruments as well as for their weighted average.The emission estimates are based on operational version 2 OMI and OMPS Principal Component Analysis (PCA) retrieval algorithm SO2 slant column density (SCD) data (Li et al., 2020) as well as on new TROPOMI Covariance-Based Retrieval Algorithm (COBRA) SCD data (Theys et al., 2021). A single time-independent site-specific Air-Mass Factor (AMF) value for each site was calculated (McLinden et al., 2014) and applied consistently to each satellite SCD dataset to derive SO2 vertical column densities (VCDs=SCDs/AMFs). The emission estimate method is based on a fit of satellite VCDs to an empirical plume model developed to describe the SO2 spatial distribution near emission point sources. The plume model assumes that the SO2 concentrations emitted from a point source decline exponentially with distance and that they are affected by turbulent diffusion that can be described by a two-dimensional (2D) exponentially modified Gaussian function. The total SO2 mass is derived from the fit and the annual emission rate is calculated as the ratio between the total mass and the prescribed SO2 lifetime.

Version 4 is the current version of the data set. Older versions are no longer available and have been superseded by Version 4. These data are a part of MEaSUREs 2012 projects. The particular project, "Multi-Decadal Sulfur Dioxide Climatology from Satellite Instruments", is expected to produce SO2 Earth Science Data Record by means of combining measurements from backscatter Ultraviolet (BUV), thermal infrared (IR) and microwave (MLS) instruments on multiple satellites. The data represent best estimates of the volcanic and anthropogenic contribution to global atmospheric SO2 concentrations. Since SO2 is the major precursor of sulfate aerosol, which has climate and air quality impact, SO2 measurements will contribute to better understanding of the sulfate aerosol distributions and its atmospheric impact." The released data file is a long-term database of volcanic SO2 emission derived from ultraviolet satellite measurements from October 31, 1978, to present. Data are in a table format in simple ASCII format: Column Descriptions: Column 1 = Name of volcano. Column 2 = Latitude of volcano. Column 3 = Longitude of volcano. Column 4 = Altitude of volcano (km). Column 5 = Eruption year. Column 6 = Eruption month of year. Column 7 = Eruption day of month. Column 8 = Eruption style: exp = explosive, eff = effusive. Column 9 = Eruption volcanic explosivity index (nd = no data or undetermined). Column 10 = Observed plume altitude (km) where known. Column 11 = Estimated plume altitude (km) above vent: 10 km for explosive, 5 km for effusive. Column 12 = Measured SO2 mass in kilotons (= 1000 metric tons).

Version 4 is the current version of the data set. Older versions are no longer available and have been superseded by Version 4.These data are a part of MEaSUREs 2012 projects. The particular project, "Multi-Decadal Sulfur Dioxide Climatology from Satellite Instruments", is expected to produce SO2 Earth Science Data Record by means of combining measurements from backscatter Ultraviolet (BUV), thermal infrared (IR) and microwave (MLS) instruments on multiple satellites. The data represent best estimates of the volcanic and anthropogenic contribution to global atmospheric SO2 concentrations. Since SO2 is the major precursor of sulfate aerosol, which has climate and air quality impact, SO2 measurements will contribute to better understanding of the sulfate aerosol distributions and its atmospheric impact."The released data file is a long-term database of volcanic SO2 emission derived from ultraviolet satellite measurements from October 31, 1978, to present.Data are in a table format in simple ASCII format:Column Descriptions:Column 1 = Name of volcano.Column 2 = Latitude of volcano.Column 3 = Longitude of volcano.Column 4 = Altitude of volcano (km).Column 5 = Eruption year.Column 6 = Eruption month of year.Column 7 = Eruption day of month.Column 8 = Eruption style: exp = explosive, eff = effusive.Column 9 = Eruption volcanic explosivity index (nd = no data or undetermined).Column 10 = Observed plume altitude (km) where known.Column 11 = Estimated plume altitude (km) above vent: 10 km for explosive, 5 km for effusive.Column 12 = Measured SO2 mass in kilotons (= 1000 metric tons).

The OMPS-NPP L2 NM Sulfur Dioxide (SO2) Total and Tropospheric Column swath orbital collection 2 version 2.0 product contains the retrieved sulfur dioxide (SO2) measured by the Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) sensor on the Suomi-NPP satellite. A direct vertical column fitting (DVCF) algorithm is used to retrieve the SO2 total column amount and column amounts in the lower (centered at 2.5 km), middle (centered at 7.5 km) and upper (centered at 11 km) troposphere, as well as the lower stratosphere (centered at 16 km). Each granule contains data from the daylight portion for a single orbit or about 50 minutes. Spatial coverage is global (-90 to 90 degrees latitude), and there are about 14 orbits per day each with a swath width of 2600 km. There are 35 pixels in the cross-track direction, with a pixel resolution of about 50 km x 50 km at nadir. The files are written using the Hierarchical Data Format Version 5 or HDF5.

The Aura Ozone Monitoring Instrument (OMI) level 2 sulphur dioxide (SO2) total column product (OMSO2) has been updated with a principal component analysis (PCA)-based algorithm (v2) with new SO2 Jacobian lookup tables and a priori profiles that significantly improve retrievals for anthropogenic SO2. The data files (or granules) contain different estimates of the vertical column density (VCD) of SO2 depending on the users investigating anthropogenic or volcanic sources. Files also contain quality flags, geolocation and other ancillary information. The lead scientist for the OMSO2 product is Can Li. The OMSO2 files are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the daylit half of an orbit (~53 minutes). There are approximately 14 orbits per day. The resolution of the data is 13x24 km2 at nadir, with a swath width of 2600 km and 60 pixels per scan line every 2 seconds.

The TROPESS Chemical Reanalysis Surface Total SO2 emissions Monthly 2-dimensional Product contains sulfur dioxide emissions from the total of all sources. The data are part of the Tropospheric Chemical Reanalysis v2 (TCR-2) for the period 2005-2021. TCR-2 uses JPL's Multi-mOdel Multi-cOnstituent Chemical (MOMO-Chem) data assimilation framework that simultaneously optimizes both concentrations and emissions of multiple species from multiple satellite sensors. The data files are written in the netCDF version 4 file format, and each file contains a year of data at monthly resolution, and a spatial resolution of 1.125 x 1.125 degrees. The principal investigator for the TCR-2 data is Miyazaki, Kazuyuki.

The OMPS-N20 NM PCA SO2 Step1 Total Column 1-Orbit L2 Swath 17x13km collection 1 product contains the retrieved sulfur dioxide (SO2) measured by the Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) sensor on the NOAA-20 (JPSS-1) satellite. The product is based on the NASA Goddard Space Flight Center principal component analysis (PCA) spectral fitting algorithm (Li et al., 2013, 2017) used to retrieve the SO2 total column amounts assuming different SO2 plume heights, including the boundary layer (lowest 1 km of the atmosphere), the lower (centered at 3 km), middle (centered at 8 km) and upper (centered at 13 km) troposphere, as well as the lower stratosphere (centered at 18 km). Each granule contains data from the daylight portion for a single orbit or about 50 minutes. Spatial coverage is global (-90 to 90 degrees latitude), and there are about 14 orbits per day each with a swath width of 2600 km. There are 104 pixels in the cross-track direction before February 13, 2019 with a pixel resolution of about 17 km x 17 km at nadir. Since then, the pixel resolution has been enhanced to 17 km x 13 km at nadir, with 140 pixels in the cross-track direction. The files are written using netCDF version 4.

The Aura Ozone Monitoring Instrument (OMI) level 2 sulphur dioxide (SO2) total column product (OMSO2) has been updated with a principal component analysis (PCA)-based algorithm (v2) with new SO2 Jacobian lookup tables and a priori profiles that significantly improve retrievals for anthropogenic SO2. The data files (or granules) contain different estimates of the vertical column density (VCD) of SO2 depending on the users investigating anthropogenic or volcanic sources. Files also contain quality flags, geolocation and other ancillary information. The lead scientist for the OMSO2 product is Can Li.The OMSO2 files are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the daylit half of an orbit (~53 minutes). There are approximately 14 orbits per day. The resolution of the data is 13x24 km2 at nadir, with a swath width of 2600 km and 60 pixels per scan line every 2 seconds.