The London VAAC is responsible for monitoring and forecasting the movement and dispersion of volcanic ash originating from volcanoes in the north-eastern part of the North Atlantic Ocean.
Although this is a relatively small area, it covers some of the busiest airways in the world. A volcanic eruption on Iceland can quickly affect a large area of airspace, as strong winds spreading the ash downwind from the volcano. Air traffic control organisations need to react quickly to the forecasts issued by the VAAC so that aircraft can be diverted onto alternative safe tracks.
During a volcanic eruption on Iceland, the London VAAC liaises closely with the Icelandic met. service, which itself is in close contact with the Nordic Volcano Institute. The London VAAC has access to the latest observational data as they emerge.
This may be data from:
Often, visual observations originate from aircraft in the vicinity.