Minimal Saharan Dust is present across Trinidad and Tobago at this time but dust levels are set to marginally increase after mid-week across the region.
What you need to know
— Saharan Dust Surges: A mild to moderate concentration surge of Saharan Dust is forecast to arrive across Trinidad and Tobago by Thursday, April 27th, 2023 with fluctuating concentrations into next week. Another mild to moderate surge is forecast to arrive by May 2nd, 2023.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to fluctuate between good and moderate, with further reductions possible during high-traffic periods as well as in the vicinity of bushfires.
— What Should You Do: Sensitive groups may need to take the necessary precautions, particularly during high-traffic periods and in the vicinity of bushfires.
Current AQI Levels Across T&T
Based on information from official air quality monitoring stations from the Environmental Management Agency (EMA), San Fernando is reporting moderate air quality levels. The stations located at Signal Hill, Tobago, as well as Arima, Point Lisas, and Beetham, Trinidad, are not reporting PM2.5 and PM10 data.
These measurements are based on PM2.5 (particulates the size of 2.5 micrometers and smaller, usually associated with increases in Saharan Dust, vehicle exhaust, and smoke) and PM10 particulates.
Over the last 24 hours, visibility remained unaffected by Saharan Dust and smoke at the A.N.R. Robinson International Airport at Crown Point, Tobago, and the Piarco International Airport, though rainfall and low-hanging clouds have reduced visibility at times.
Saharan Dust Forecast
Next Surge: Late Wednesday, April 26th into Thursday, April 27th.
Saharan Dust levels are set to remain at minimal levels through April 26th, 2023. During the overnight hours, into April 27th, 2023, Saharan Dust is forecast to increase across the region with mild to moderate concentrations.
Concentrations are forecast to fluctuate through the remainder of the 10-day period, with another mild surge forecast to arrive by May 2nd, 2023.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to fluctuate between good and moderate, with further reductions possible during high-traffic periods as well as in the vicinity of bushfires.
What does this mean for you?
The air quality is forecast to be lowered, especially during high traffic periods, particularly between 6:00 AM and 9:00 AM and again from 3:00 PM through 6:30 PM, as well as during times of blowing smoke and dust from bushfires.
The surges of dust during this time of year are due to the Harmattan, a season in the West African subcontinent that occurs between the end of November and the middle of March. During this season, a predominant northeasterly trade wind (dubbed the Harmattan Winds) blows from the Sahara Desert over Western Africa into the Gulf of Guinea.
During this period, a ridge of high pressure stays over the central Sahara Desert, and the Intertropical Convergence Zone (ITCZ) remains over the Gulf of Guinea. The Harmattan wind accelerates when it blows across the mountain massifs of Northwest Africa. If its speed is high enough and it blows over dust source regions, it lifts the dust and disperses it.
Dust that makes it into the upper levels of the atmosphere can then get transported across the Atlantic Ocean and affect the Eastern Caribbean. These Saharan Dust outbreaks tend to be milder in the Eastern Caribbean than the dust outbreaks associated with West African thunderstorms driving dust into the upper atmosphere from April through November.
