The Copernicus Atmosphere Monitoring Service (CAMS*) has unveiled its Aerosol Alerts service. Launched in February 2024, the new service provides daily aerosol alerts based on aerosol optical depth and particulate matter observations. Users can also sign up to receive customised alerts covering geographical areas and aerosol species of interest. Let’s take a closer look.

The free-to-use Aerosol Alerts service, developed by a team at the Norwegian Meteorological Institute, uses forecasts provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System to provide daily aerosol alerts up to three days in advance. The alerts are computed based on an evaluation of each forecast, with different thresholds used to detect anomalies relative to reference levels and to describe events.

For example, for alerts based on aerosol optical depth, which is a measure of the total amount of aerosol in a vertical column of the atmosphere, the forecasts are compared against a climatology computed using the CAMS global reanalysis of atmospheric composition averaged between 2003 and 2018, while alerts based on particulate matter surface concentrations are compared against given absolute values. The system triggers three levels of alert – high, very high and extreme – when certain pre-determined thresholds are exceeded.

The tool’s homepage has a global map where the default ‘all species’ view shows each aerosol species (dust, sea salt, sulphate, organic matter, and black carbon) simultaneously, with arrows indicating prevailing winds. In the settings, users can select individual aerosol species, change the view from 2D to 3D, adjust the animation speed, use up-to-date visible imagery from satellites, compare model forecasts with observations, and make other adjustments. Users also have access to an evaluation of the forecast performance, allowing them to explore the model’s performance in forecasting the aerosol alerts by region and season.

Link to the product: https://aerosol-alerts.atmosphere.copernicus.eu/