A surge of Saharan Dust has returned to Trinidad, Tobago, and the Lesser Antilles over the last 24 hours. While higher concentrations are forecast to remain north of Trinidad and Tobago, air quality and visibility will be affected.
What you need to know
— Saharan Dust Surges: A moderate concentration of Saharan Dust is present across Trinidad, Tobago, and the Lesser Antilles on Tuesday, October 11th, 2022. Milder surges of dust are forecast through the next ten days, with higher concentrations generally remaining north of the country.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago will fluctuate between good and moderate levels. Through Wednesday, October 12th, 2022, air quality levels could occasionally dip to levels that are unhealthy for sensitive groups.
— What Should You Do: Sensitive groups may need to take the necessary precautions, particularly during high-traffic periods. The general population will remain unaffected.
Current AQI Levels Across T&T
The Environmental Management Agency (EMA) air quality monitoring stations at Port of Spain and San Fernando have recorded good to moderate air quality levels over the last 24 hours, while at Point Lisas, air quality remains at good levels. The station at Signal Hill has not reported data in the last 24 hours.
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 dipped to seven kilometers at the Piarco International Airport but remained at or above ten kilometers at A.N.R. Robinson International Airport at Crown Point, Tobago, outside of shower and thunderstorm activity.
Saharan Dust Forecast
Ongoing Surge: Tuesday, October 11th, 2022
A moderate to a high-concentration surge of dust arrived across Trinidad, Tobago, and the remainder of the Lesser Antilles from early Monday, October 10th, 2022. Concentrations are forecast to fluctuate through much of this week, with some improvement forecast by the weekend. However, periodic surges of dust, with higher concentrations remaining north of Trinidad and Tobago through the next ten days.
Air quality levels will fluctuate between good and moderate, occasionally dipping to levels that are unhealthy for sensitive groups, mainly until Wednesday. Horizontal visibility may dip as low as 7 kilometers outside of shower and thunderstorm activity.
What does this mean for you?
The air quality is forecast to be lowered primarily during high traffic periods, particularly between 6:00 AM and 9:00 AM and again from 3:00 PM through 6:30 PM.
We’re in a period where the Intertropical Convergence Zone and tropical waves and occasional tropical cyclones may shield Trinidad and Tobago from the Saharan Dust events. While Tropical Waves play a notable role in moving dust across the Atlantic and the Eastern Caribbean, these periodic tropical waves also improve air quality.
The concentration of the dust that follows the wave depends on its strength as it moves off the West African Coast. This is because of stronger thunderstorms across Central Africa. As strong winds move downward and outward from these thunderstorms, the wind kicks up dust as it moves across parts of the Saharan Desert and transports it into the upper atmosphere. This “plume” of dust follows the axis of the wave as it progresses westward into the Atlantic.
Dust that makes it into the upper levels of the atmosphere can then get transported across the Atlantic Ocean. The plumes of dust eventually affect the Eastern Caribbean.
Larger, more concentrated plumes of Saharan dust begin in April and continue through November.
