Monitoring atmospheric composition & climate
MACC forecasts of wild fire smoke plumes

On 7 July 2012 the sky above Seattle in the American north-west filled with a smoky haze, which lasted for several days. MACC-II forecasts showed that this smoke was not originating from the large fires in Colorado, but from even larger fires in Russia. Various news articles combined information from MACC-II with observations to illustrate the impact of this large plume of biomass burning aerosol and carbon monoxide (KPLU, US Air Quality Smog Blog, Pique, Cliff Mass Weather Blog).

The animation below shows the fire activity and smoke plumes in Russia and China in June/July 2012 and the consecutive transport of smoke across the Pacific. The MACC GFAS assimilation of Fire Radiative Power observations are superimposed over the combined organic matter and black carbon fields in the MACC global aerosol assimilation, which combines the smoke emissions calculated in GFAS with inventories of anthropogenic emissions and aerosol optical depth observations from space. Both types of observations are performed by the satellite-based MODIS instruments and NASA has provided the observation data.



The MACC-II forecast of carbon monoxide (CO) also illustrates the large extent of the plume. The figures below show the 3-day forecast made on 4 July 2012 of CO at 850 hPa (approx. 1500 m) on the left and the analysis (model constrained by observations) for 7 July 2012 on the right. The figures show that the 3-day forecast already provided a very realistic picture of the situation on 7 July when the plume hit the American north-west.



atrain-3_small.gifThe images below show some first validation of the MACC-II forecast results using observations from the NASA CALIPSO satellite lidar instrument ( The instrument flew over the plume on 7 July 2012 (the satellite track is illustrated in the image on the right) providing good observations of aerosol and clouds.

The top left plot shows the satellite observations of backscattered radiation and the plot on the top right shows the equivalent values coming from the model forecast. Clouds are visible in the observation plot by the white-masked areas and aerosol is shown with the colour scale.

The bottom two plots show the actual model aerosol (coloured) and cloud (grey) on the left and carbon monoxide concentrations on the right. This validation shows that the MACC-II forecasts of this smoke plume were indeed quite realistic.