GASSP aims to create the largest ever model-ready database of global aerosol microphysics measurements. Although several measurement networks provide access to high quality well-documented data, like ACTRIS, a project like GASSP is still needed because:
- Vast amounts of data exist outside major measurement networks, mostly held by individual investigators.
- Even when data are already available for download, the many different data formats makes it difficult to automate the process of model-observation comparison. So far, we have read and converted over ten different data formats.
- In many cases the necessary “position files” (e.g., of aircraft position) have not been merged with the aerosol measurement data, and may even be on a different time base.
- Data collection focuses on in situ measurements that can provide detailed information about aerosol microphysical properties such as particle number concentrations, size distributions and chemical composition.
- The emphasis is on collecting and harmonising datasets that are not available in other databases, mostly direct from collaborating experimentalists.
- All data are being converted to a standard NetCDF format with rich metadata. Data are held at the Centre for Environmental Data Archival (CEDA) in the UK. A data access protocol will be developed with the data providers in 2016.
Extensive and sometimes long-term measurements of aerosol microphysical quantities have been made at surface sites across Europe, North America and at many other locations around the world. The ACTRIS project (Aerosols, Clouds, and Trace gases Research InfraStructure Network) is a European Project aiming at integrating European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds, and short-lived gas-phase species. The Global Atmosphere Watch (GAW) programme of the World Meteorological Organization also has long-term measurements of aerosols at many remote locations around the world.
GASSP will use a wide array of aerosol measurements from several research aircraft that have operated in a large number of measurement campaigns. Aircraft include the German Falcon F20, operated by DLR (project partner Andreas Minikin), the NOAA P3, the UK’s BAe 146 (operated by the Facility for Airborne Atmospheric Measurements, FAAM) , the NASA WB-57F and the NSF/NCAR GV (pictured), as well as commercial aircraft fitted with aerosol instrumentation in the CARIBIC experiment.
Extensive aerosol data have been collected from shipborne measurements stretching back to 1992 by the NOAA Pacific Marine Environment Laboratory (PMEL, project partner, Trish Quinn). Campaigns include ACE-1, ACE-2 and ACE-Asia, starting in 1995, to the more recent VOCALS. Almost every environment has been studied, from the Arctic, to the Antarctic and including measurements in remote and polluted environments. These measurements have led to much of our fundamental understanding of aerosol sources and behaviour in marine environments.
Global coverage of aerosol measurements used in GASSP
As of October 2015, we have collected and processed data from 130 field campaigns and 270 ground stations. The datasets cover particle concentrations (CPC), size distributions, black carbon concentrations (SP2), CCN concentrations at several supersaturations, aerosol composition (AMS) and PM2.5.
The dataset of aerosol measurements being used in GASSP is changing all the time. Click on each thumbnail below to scroll through maps for various aerosol quantities.