Considering that it is a fixture of life in California, it’s remarkable how much remains unknown about the fog that regularly flows over the coast from the Pacific Ocean. But a collaboration between researchers throughout the state hopes to change that.With a five-year, $3.7 million grant from the Heising-Simon Foundation, the Pacific Coastal Fog Research project is poised to lift the veil on the rather mysterious meteorological phenomenon. The scientists will record the fog’s chemical composition, examine how it helps support redwood forests and other ecosystems, and look at the possible effects of climate change and pollution from human activities.Sara Baguskas and her colleagues at San Francisco State University are one of five teams working on the project. Starting in the spring, they will head out to locations on the coast from San Diego to Humboldt County, carrying towering fog collectors and a slew of sensors measuring temperature, humidity, wind speed and solar radiation.“It’s the first time we have been funded to carry out interdisciplinary research at a scale that really allows us to answer fundamental questions regarding coastal fog dynamics and impacts on ecosystems,” Baguskas said.The fog collectors are tree-like structures with a fine mesh net spanning between their branches. Water collected in the mesh drips down and is collected into troughs. Baguskas and her colleagues will deploy covariance towers — metallic structures that continuously measure carbon and water concentrations in the air — and use the data to compare fog events in different places at the same time.“With this, we can begin to make connections between fog events and the ecosystem response to disentangle the ephemeral and nebulous nature of fog events and make it a little more concrete,” Baguskas said.Meanwhile, a team led by environmental chemist Peter Weiss-Penzias of UC Santa Cruz will study the fog’s composition, looking for toxic chemicals.This past summer, they collected preliminary data for the project in several locations along the coast, including Pacifica and Santa Cruz. They found highly toxic methyl mercury, which is actually a natural component of the fog.Methyl mercury is formed by bacteria in the depths of the ocean. But at the coast, winds push surface water out to sea, allowing colder, deeper water to rise to the surface. Coastal fog — which forms when moist air condenses over the cool, ocean water and drifts toward shore — then picks up water evaporating from the ocean surface, allowing methyl mercury to hitch a ride onto land.To study how methyl mercury gets deposited, the researchers take samples of lichens, dissolving them in nitric acid to extract mercury and other metals. Not surprisingly, preliminary studies have found that the amount of methyl mercury in lichens is highest near the coast and rapidly drops off farther inland.Keep Reading
