After a week of fairly dust-free conditions, Saharan Dust has returned to Trinidad and Tobago, with another surge arriving by Monday, reducing both visibility and air quality.
What you need to know
— Saharan Dust Surges: A mild to moderate concentration of Saharan Dust is present across Trinidad, Tobago, and the Windward Islands on Friday, October 7th, 2022. A moderate to high-concentration surge is forecast to arrive across the Lesser Antilles by Monday, October 10th, 2022, with elevated concentrations through next week. A secondary, milder surge is forecast to arrive across the Lesser Antilles by Saturday, October 15th, 2022, and across Trinidad and Tobago by Sunday, October 16th, 2022.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago will fluctuate between good and moderate levels. From Monday, October 10th, 2022, through mid-week, 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 remained near or above ten kilometers at the Piarco International Airport and A.N.R. Robinson International Airport at Crown Point, Tobago, outside of shower and thunderstorm activity.
Saharan Dust Forecast
Next Surge: Monday, October 10th, 2022
A moderate to a high-concentration surge of dust is forecast to arrive across Trinidad, Tobago, and the remainder of the Lesser Antilles from early Monday, October 10th, 2022. Concentrations are forecast to fluctuate through much of next week, with some improvement forecast briefly by Saturday, October 15th, 2022. A secondary, milder surge of dust is forecast to arrive across Trinidad and Tobago by Sunday, October 16th, 2022
Air quality levels will fluctuate between good and moderate, occasionally dipping to levels that are unhealthy for sensitive groups, mainly between Monday and Wednesday next week. 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.
