The National Weather Service referred to it as “super fog,” which was caused by a mix of dense smoke from fires in the marshy wetlands of southern Louisiana and the typical fog that lingers in the air on calm, chilly mornings.

This week, a dangerous mix occurred when smoke from a nearby marsh fire in New Orleans combined with heavy fog, making it difficult to see on the highways. This resulted in several terrible accidents, transforming a portion of Interstate 55 near New Orleans into a wrecked and burnt vehicle graveyard.

According to authorities, a total of 158 cars were part of the incident. There were 25 documented injuries and the number of fatalities from the accident on Monday has reached seven as of Tuesday afternoon.

Is it Super Fog or Smog?

According to the National Weather Service, super fog and smog are two forms of fog. However, smog is created when fog mixes with smoke from pollutants, typically seen in urban areas with high levels of cars or industrial activity. This can decrease visibility and be harmful to health.

The weather service defines “super fog” as fog that is intensified by smoke from moist, burning organic material. This can significantly reduce visibility to under 10 feet (3 meters).

How frequently does super fog occur?

According to Tyler Stanfield, a meteorologist at the New Orleans office of the weather service, super fog events are not uncommon but require a unique combination of conditions to occur. They can happen a few times each year. Fireworks may contribute to these conditions, and in the past, super fog has been observed during Fourth of July and New Year’s celebrations.

Stanfield explained that on Monday, there were light winds and high pressure in the region. This caused moisture to be trapped near the ground, creating what he called a “typical fog setup.” The burning of damp leaves and brush led to extremely poor visibility.

Is it frequent for fires to occur in the marshes of Louisiana?

According to Louisiana Agriculture Commissioner Mike Strain, marshes, despite being classified as wetlands, are prone to drying out. This is especially true during periods of drought, which have led to wildfires in both marshes and timberland. Strain explains that when the dry grass catches fire, it not only burns the surface layer, but also the crust and peat layer below.

Fires like this happen annually in the southern region of Louisiana. They may be a result of natural causes such as lightning or human activity, such as hunters trying to scare out game, officials conducting controlled burns to stimulate new plant growth, or occasionally deliberate acts of arson. These fires typically occur in isolated and challenging terrain, making it challenging to contain them once they spread.

According to Stanfield, these fires are not necessarily large and uncontrollable, but they burn slowly and produce smoke. He also mentioned that they can persist for weeks or even months.

According to Stephen Murphy, director of Tulane’s School of Public Health and Tropical Medicine’s disaster management program, the increase in frequency of this phenomenon may be linked to climate change. He also noted that the current drought conditions in the area have contributed to the spread of the marsh fire.

HAVE CONDITIONS IMPROVED?

By Monday evening, the dense fog had dissipated. The combination of strong winds and high pressure heading towards Georgia has eliminated the possibility of another dense fog occurrence. Additionally, according to Strain, efforts are ongoing to put out the marsh fire near New Orleans, which has been a major source of the smoke that caused accidents on Monday.

According to Strain, we have two pumps that are releasing a large amount of water, causing flooding in the entire area. Even after releasing the smoke, there is a possibility of it still burning. Our goal is to significantly decrease the amount of smoke.

___

The Associated Press receives assistance from multiple private foundations for its coverage of climate and environmental issues. Learn more about the AP’s efforts in this area here. The AP is solely responsible for all of its content.

Source: wral.com