Following the eruption of the Eyjafjallajökull volcano in 2010 there was significant disruption to UK and European airspace from the ash cloud. The eruption of the Grimsvötn volcano in 2011 also resulted in some disruption to air travel.
In order to be in a high state of readiness for any future volcanic eruptions, and also provide a platform capable of responding to a wider range of civil contingency events, the Met Office Civil Contingency Aircraft (MOCCA) has been commissioned.
The aircraft will be operated by the Met Office on behalf of the Civil Aviation Authority (CAA), and in a partnership between Cranfield Aerospace and DO Systems.
The aircraft is a flexible twin engine pressurised Cessna 421 which operates with either one or two pilots and one scientist. It has been specifically chosen because it operates with piston engines at cooler temperatures. This means it is able to fly into higher concentrations of volcanic ash.
The aircraft will be used to monitor ash during any future volcanic ash incidents. It will also be scrambled to operate in a range of situations where expert sampling of air pollutants may be required, such as oil fires like the one at Buncefield, ensuring the safety of those in the air and on the ground.
The aircraft is designed to monitor and measure gases and aerosols in the atmosphere. These include pollutants like volcanic ash, dust and smoke.
The aircraft is currently configured to measure gases and aerosols in the atmosphere.
On a typical flight the aircraft would initially fly above or below an ash layer looking at the position of the ash layers with the lidar. The aircraft will then fly in to the ash layers and measure the size and number of ash particles using the laser scattering probe on the wing. This probe works by firing a laser beam that hits the ash particles which scatter the laser light in different directions. The amount of laser light scattered gives information on the size of the particles.
Gases can be measured in flight or captured in Tedlar bags for analysis on the ground.
The aircraft will be fully integrated in to the Met Office Hazard Centre, where the observations will be received direct via satellite by the forecasting and incident response teams.
This enables the full forecasting capability of the Met Office to be used in directing the aircraft's flight and also enables the forecaster and incident response teams to make informed decisions about the potential impacts of the ash cloud.
The observations made by MOCCA will be used to give better validation of the world-leading dispersion models used by the Met Office, which help airlines to fly safely when a volcanic eruption occurs.