In addition to heat, the orientation of Atlantic High is causing winds to transport dry, dusty and unhealthy air from the Sahara Desert, in Africa, to the Caribbean.
The dust streams across the Caribbean all year round, via the generally easterly wind flow between Africa and the our region. The flow of dust peaks in June and decline to a minimum in December. It is most abundant over the period May to September, when it is often times transported by tropical waves, which originate over Africa.
The dust is a major health concern. Research has shown that the dust causes asthmatic flare ups and other respiratory complaints. The impact of the dust on health is said to be caused mainly by the bacterial and fungal spores it contains.
Of much graver concern to health professionals is the fact that the dust also contains chemicals such as pesticides and polycyclic aromatic hydrocarbons, which are known to be very harmful to human health.
Research has also shown that the dust may be harmful to coral reefs. According to retired geologist Gene Shinn, “Our hypothesis is that much of the coral reef decline in the Caribbean is a result of pathogens transported in dust from North Africa”.
The dust has also been credited for algae blooms in a phenomenon called “red tide”. This sought of bloom has been responsible for the death of millions of fish and other marine life, in the past.
The Saharan dust is not all bad. In addition to being a hurricane blocker, it is good for the environment. The dust is rich in plant nutrients and is believed to be largely responsible for the fertility of the Amazon Rainforest.
This air is notorious for “stifling” shower activity and in the past has triggered or exacerbated droughts in the region and further afield. It’s also a hurricane blocker – it hinders or weakens tropical cyclones (depressions, storms and hurricanes).
Depending on the amount of dust, the reflection and refraction caused can result in magnificent sunsets.
The dust is not predictable beyond days; thus, its impact on the upcoming hurricane season is unknown. However, once present, it could combine with El Nino to produce a very quiet hurricane season. Additionally, it could combine with El Nino to cause well below normal rainfall for the Caribbean.
So the Saharan dust is not a simple matter; it not only causes hazy skies, but among other things, causes disease. It would be wise to take as much precaution, as possible, to avoid inhaling it.
According to Monitoring Atmospheric Composition and Climate, this particular episode of Saharan dust will diminish to negligible levels across Antigua and the rest of the northeast Caribbean by Friday and most of the rest of the area by Saturday. The exception may be some of the southern islands such as Barbados, Grenada and Trinidad and Tobago.
We will be monitoring.