A large amount of dust has been blown towards the UK from the Sahara Desert where strong winds have blown up sand into a dust storm.
The video below shows how the dust is blown up and carried to the UK. The dust, shown in pink within the red circle, is carried within clouds, shown in red, to the UK, where it falls within rain showers. (Video from the Met office)
Saharan dust is a contributing factor to air quality as well as pollution levels. The dust brings in pollution from Europe and the high pressure over the UK traps it in place. This has resulted in the highest smog alert warnings for London and much of southern UK.
Air pollution forecast for April 2nd 2014. Purple is very high air pollution, orange moderate and low pollution in green. Source: Defra
The Department for Environment, Food and Rural Affairs (Defra) said high to very high air pollution was expected across East Anglia, parts of south-east England and around the Humber on Tuesday. High levels of air pollution in parts of the UK are expected to last until the weekend.
Paul Hutcheon at the Met Office said “We usually see this happen several times a year when big dust storms in the Sahara coincide with southerly winds to bring that dust here.”
Defra has warned that adults and children with lung and heart problems, including older people, should avoid excessive strenuous activity for the next week or so. It also warned that “people with asthma may find they use their reliever inhaler more often”.
Defra’s Recommended Health Advice and Actions
Health advice and precautions. Source: Defra