StreamAIR is the C-CAPS real time Earth Observation (EO) Data and Forecasting System with integrates observation and modelling of atmospheric composition, air pollutants, essential climate variables and meteorology. StreamAIR has evolved from the Mace Head ( data system and now integrates the national observing AEROSOURCE advanced AQ network, the transboundary air pollution network, the ICOS and ACTRIS ESFRI networks works with the StreamAIR-AQ, MET & ASH forecasting systems as well as forming an essential high-resolution marine meteorology EO component of MaREI (

StreamAIR-AQ is air quality/atmospheric composition forecasting and realtime data system designed to monitor, observe and forecast Air Pollution over Europe and is operated on a grid resolution of 25 km x 25 km. The modelling component is based on WRF-CHEM.

Daily forecasts are published between: 18:45 pm-19:50 pm

  • Zoomable 5-day weather forecast 2D map over Europe with user-selectable outputs for key weather variables (e.g. 2 metre temperature, rain, surface pressure charts, snow, relative humidity, wind speed and direction, and sunshine). Using the forward, backwards, and play buttons, the user can step forward or backward hour by hour, or it can auto-cycle the 72 hours.
  • Zoomable 5-day air pollution forecast 2D map over Europe with usable selectable outs for key air pollutants (e.g. Air Quality Index, reactive gases including ozone, SOx, NOx, PM2.5, PM10, and ultra-violet radiation).
  • 48 hour forecast for user-selected point locations are activated by mouse click on a computer or finger tap in mobile device. When activated, three display graphs pops-ups (one meteogram, one Particulate Matter plot, and one Reactive Gas plot).
  • In each graph, each of the parameters has a colour-coded label matching its graphical trace. Clicking on the parameter label either hides or displays the graphical trace. When the cursor is run along a particular parameter’s trace, the instantaneous value is displayed in the colour coded label.

StreamAIR automatically classifies Air Quality and Weather conditions into four classifications of progressively worsening conditions.

Air quality alert - Good Air quality - Fair Air quality - Poor Air quality - Very poor
Air quality is satisfactory and poses little or no health risk. Enjoy usual outdoor activities. People who are unusually sensitive to ozone or particle pollution may experience respiratory symptoms. Everyone may experience more serious health effects. Entire population is even more likely to be affected by serious health effects.

Normal conditions
Gusting <22 ms-1
Less than Gale Force
Rain <30mm in 24 hrs
Snow 0 cm
Temperature < -3°C or <27°C
Moderate conditions
Wind >14 ms-1
Gusting >25 ms-1
Gale Force 8
Rain >30 mm in 24 hrs
Snow >3 cm
Temperature < -4°C or >27°C
Potentially significant conditions
Wind >18 ms-1
Gusting >30 ms-1
Storm Force 11
Rain >50 mm in 24 hrs
Snow >3 cm
Temperature < -5°C or >30°C
Extreme conditions
Wind >22 ms-1 Gusting >36 ms-1
Violent Storm Force 11
Rain >70 mm in 24 hrs
Snow > 8cm
Temperature < -10°C or >27°C

Summary Weather Icons

Rain Snow Wind Normal Hot Cold Humidity

WRF-CHEM is the Weather Research (WRF) model coupled with Chemistry. The model simulates the emission, transport, mixing, and chemical transformation of trace gases and aerosols simultaneously with the meteorology. The model is used for investigation of regional-scale air quality, field program analysis, and cloud-scale interactions between clouds and chemistry. The WRF-V code is developed and maintained by NOAA/ESRL/GSD in strong collaboration with other research groups at NOAA/ESRL, NCAR, PNNL, NASA and ERDC.

Here we use the WRF-CHEM, model to simulate meteorology and air quality over Europe on a coarse grid that extends from 35° N to 63° N in latitude and from 22° W to 19° E in longitude. The horizontal resolution is 25 km and 29 vertical levels. The initial boundary meteorological conditions are provided by the European Centre for MediumÔÇÉrange Weather Forecast (ECMWF). The model is run daily, running time is between 6-8 hours.