A major scientific field study of sea fog off the east coast of Canada is about to begin.
The research is funded by the US Department of Defense and hopes to better predict one of the most unpredictable weather phenomena: fog.
Fog can quickly ruin visibility anywhere, from ports to highways to airports, and can interfere with weapons systems. But how it is created is not deeply understood, which is one reason why fog can only be predicted hours in advance, if at all.
“Prediction is critical because each year in Canada, about 50 to 60 people die due to visibility fog-related problems,” said Ismail Gultepe, a research scientist with the Department of Environment and Climate Change Canada who is participating in the project.
The researchers chose to study the Grand Banks region in the North Atlantic because it is one of the foggiest places in summer, along with the Yellow Sea off China. In 2023, the research study will shift to the Yellow Sea.
“I would say this is the largest fogging project ever undertaken to date,” said Joe Fernando of Notre Dame University in Indiana, who is leading the study.
He spoke from inside a hangar at Halifax Stanfield Airport, where more than four tons of atmospheric measurement equipment was being flown to Sable Island, 300 kilometers southeast of ‘Halifax.
Instruments will also be deployed from the Irving-owned offshore supply vessel Atlantic Condor, which was chartered for a month-long mission in July. The ship will sail from Sable Island to the Grand Banks.
“The overall goal of the project is to improve the predictability of sea fog as much as possible. It is very difficult to predict, one of the least predictable in marine meteorology,” Fernando said.
The mystery of the fog
Fog is created when water droplets form around particles, but the interaction of all atmospheric processes involved is not well understood.
“The fog changes quickly and that’s the difficulty. It comes quickly, goes quickly, and we don’t know how long it’s going to stay,” Fernando said.
The United States Office of Naval Research commissioned the $7.5 million study. The data collected is not classified.
Fernando said an important part of the study includes “propagation of the directed energy laser beam through the atmosphere so that incoming targets can be canceled out by the laser beam.”
Dozens of scientists are involved, including Canadian researchers from Environment and Climate Change Canada, York University, the Department of Fisheries and Oceans, the Marine Environmental Observation, Prediction and Response Network and the Dalhousie University in Halifax.
The Atlantic Condor will carry instruments from Rachel Chang’s laboratory.
The Dalhousie aerosol scientist will measure the size and number of particles in the atmosphere and their impact on fog visibility and duration.
She is also studying the droplets that form around a salt particle and those that form around industrial emissions blown into the area.
“That’s actually the core of what I’m really interested in is whether the source of the particles – whether they’re from the ocean or emissions – and whether that really affects visibility or not.”
Ismail Gultepe of the Department of Environment and Climate Change Canada is also studying the impact of climate change on the creation and disappearance of fog. The more water vapor created in the open ocean, the more fog there is, he said.
“That’s why we like to know how fog survives and how weather conditions change,” Gultepte said, adding that an important outcome will be improved modeling to predict fog.
The project is known as FATIMA, for Fog and Turbulence Interactions in the Marine Atmosphere.
The study will measure wind turbulence, fog microphysics and chemistry, cloud height, water vapor and other conditions. It will use weather balloons, radar and lidar.
The Atlantic Condor will also deploy a small, remote-controlled vessel and glider that will perform measurements in the high seas and lower atmosphere.