Saharan dust is currently escaping the confines of the desert and making a break for it over the Atlantic Ocean towards South America.
Below is a true colour image from the MODIS instrument on the TERRA satellite from this morning (6th June). You can see the dust from the desert over the ocean; note the constrast between the darker blue ocean surface and the lighter shade where the dust resides.
Below is the same image but with Aerosol Optical Depth (AOD) overlaid. This provides a measure of the total amount of aerosol particles in the atmosphere. The red portions are values above 0.7, which is quite elevated (anything above 0.3 would be fairly polluted).
Such incidences aren’t particularly unusual and the dust actually acts as a natural fertiliser for the ocean! Dust from the Sahara has also been observed to reach the Amazon rainforest. There are some more satellite images here on the OMPS blog.
Saharan Dust expected to be at ground-level close to the south-east of the UK on Saturday. pic.twitter.com/BV5QBXG8Pm
— Defra Air Quality (@DefraUKAir) June 6, 2014
This follows the pollution episode that struck the UK in early April, where Saharan dust combined with pollution from continental Europe and the UK. On this occasion though, thunderstorms are expected during Saturday, which will likely reduce any build-up of pollution and also wash out the dust from the atmosphere.
A sprinkling of dust might be found on cars in the south-east should the forecasts pan out. Dust gets around.