African winds from SW – SE

A Calima wind, which brings sand from the Sahara Desert  is unpredictable so it can happen any time of the year, but it usually appears in the winter season between December and March.. It can last from 3 to 5 days or even up to a week and it is very dense, causing low visibility and extreme amounts of dust entering everywhere.

The word Calima itself originates from the Spanish word for “haze”. This haze is a layer of dust and sand brought on high winds originating from Africa. On occasion weather fronts in the south-west of the Canary Islands can increase wind-speeds even more. In these cases the Calima will escalate bringing very high temperatures with it, and is able to carry dust high above the Atlantic covering hundreds of thousands of square miles with a dense cloud of Saharan sand, sometimes  reaching the Caribbean.

DETAILS from 2020 Yacht Maya >>

February 2020 – Calima – Yacht Maya

After a pleasant crossing to Tenerife we settled in to Marina Del Sur to see what the coming wind was going to do. You could see the sky visibly darkening to an orangey-red colour and, as the wind increased, the visibility decreased.

One measure of air pollution is the amount of coarse particulate matter – or PM₁₀ – in the air close to the Earth’s surface, another is aerosol optical depth (AOD) which is a measure of how much direct sunlight is blocked by dust and haze in the atmosphere. CAMS has been tracking both and, as confirmed by Aeronet observations, the CAMS forecasts of total AOD represented the event very well, including the longer-range transport.

In the Canary Islands, air quality was severely degraded for several days as a result of the dust storms, with high measured PM₁₀ values.