A major scientific field study of marine fog off Canada’s east coast 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 obscure visibility anywhere from ports to highways to airports, and can interfere with weapon systems. But how it’s made isn’t well understood, which is one of the reasons fog can be predicted just a few hours in advance, if at all.
“Forecast is critical, because in Canada about 50 to 60 people die each year due to the visibility of fog-related problems,” said Ismail Gultepe, a research scientist with the Department of Environment and Climate Change Canada involved in the project.
Researchers chose to study the greater Grand Banks area in the North Atlantic because it is one of the mistiest places in the summer, along with the Yellow Sea off China. In 2023, the research will move to the Yellow Sea.
“I would say this is the largest fog project ever undertaken to date,” said Joe Fernando, of Notre Dame University in Indiana, who is leading the study.
He spoke from a hangar at Halifax Stanfield Airport, where more than four tons of atmospheric measurement equipment was 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 in July for a one-month mission. The ship sails from Sable Island to the Grand Banks.
“The overall goal of the project is to improve the predictability of marine fog as much as possible. It is very difficult to predict, one of the least predictable in marine meteorology,” Fernando said.
The mystery of fog
Fog occurs when water droplets form around particles, but the interaction of all the atmospheric processes involved is not well understood.
“Fog changes quickly and that’s the difficulty. It comes fast, it goes fast and we don’t know how long it will last,” said Fernando.
The US Office of Naval Research ordered the study for $7.5 million. The data collected is not classified.
Fernando said an important part of the research involves the “directed propagation of the energy laser beam through the atmosphere so that the targets entered by the laser beam are negated.”
Dozens of scientists are involved, including Canadian researchers from the Department of Environment and Climate Change Canada, York University, the Department of Fisheries and Oceans, the Marine Environmental Observation, Prediction and Response Network and Dalhousie University in Halifax.
The Atlantic Condor will carry instruments from Rachel Chang’s lab.
Dalhousie’s aerosol scientist will measure the size and number of particles in the atmosphere and how they affect the visibility and duration of fog.
She also studies droplets that form around a salt particle and those around industrial emissions blown into the area.
“That’s basically the gist of what I’m really interested in is whether the source of the particles — whether they’re from the ocean or from emissions — and whether that really affects visibility or not.”
Ismail Gultepe of the Department of Environment and Climate Change Canada is also investigating the impact of climate change on the creation and disappearance of fog. The more water vapor that forms in the open ocean, the more fog, he said.
“Therefore, we would like to know how the fog survives and changes in climatic conditions,” Gultepte said, and an important result 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 remotely piloted small craft and glider that will take measurements at the top and bottom of the ocean.
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