Monitoring atmospheric composition & climate
 
 
Canadian smoke spreading over Europe
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Biomass burning plume from Canada

10 July 2013  People in northern Europe wondering about the sometimes slightly hazy skies this month will be surprised to learn that they are looking at smoke from wildfires in Canada. The very active fire season in the Canadian boreal forests is producing large amounts of smoke. While these fires are present every summer, they are currently very widespread and strong winds over the Atlantic are moving the smoke rapidly towards north-western Europe. The weather pattern over Europe, responsible for the nice summer weather, then moves some of this smoke over middle Europe reaching as far south as Italy.

MACC-II routinely monitors emissions of smoke particles (biomass burning aerosol) and other atmospheric pollutants, such as carbon monoxide, using observations from the MODIS satellite instruments. The GFAS algorithm produces daily global maps of all detectable fires and their emissions, as shown in the figure below. These emission estimates are then fed into MACC-II’s global forecasting system for atmospheric composition producing daily 5-day forecasts of the smoke plumes, as shown in the animation. These forecasts are further constrained by merging the information from the model with aerosol and carbon monoxide observations from the MODIS, MOPITT and IASI instruments.

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Fire emissions from MACC-II GFAS system

While the smoke is currently located between 2km and 6km altitude and therefore not directly affecting European air quality, it is valuable to continuously monitor these plumes. Weather patterns change and could at any moment bring these aerosol particles and elevated carbon monoxide concentrations closer to the surface. This would then have a direct impact on air quality and visibility, as was for instance the case last year in Vancouver, Canada.

The layer of biomass burning aerosol is also clearly visible in observations from various measurement networks. Lidar observations use lasers to measure vertical profiles of aerosol and cloud particles as a function of time. The Polly network is clearly showing the layers of smoke extending over Europe as is shown in the figure below for Stockholm.

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Observations from the Stockholm Polly lidar (left) and Putbus ceilometer (right)

Ceilometers across Europe also show a clear layer of aerosol at an altitude of around 4000 meter, as shown for Putbus, Germany. These observations, together with the MACC-II forecasts, provide an interesting picture of wildfire smoke being transported from Canada and spreading out of a large area of Europe.

MACC-II routinely provides these 5-day forecasts, but also pays significant attention to the validation of the forecast products. This is to ensure that the forecasts are meaningful and can be improved where needed. Below are two figures showing carbon monoxide concentration profiles from aircraft observations (IAGOS) over Frankfurt and Paris. There are clear increases in CO between 2000 and 4000 meter for the observations (black), which are also captured by the MACC-II forecast (red).

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MACC-II forecasts of CO profiles compared to IAGOS aircraft observations