I’m on this research cruise to investigate controls on surface water chemistry that influence sea spray composition. Sea spray is generated at the ocean’s surface, from waves breaking at the beach, and also from howling winds creating choppy water with whitecaps and many, many bubbles. Sea spray is one of two major natural sources of particles in the atmosphere. Solid particles and liquid droplets in the atmosphere are called aerosols, and the other major natural source of aerosols in the world’s air is dust. Without sea spray, dust, and other aerosols in the atmosphere, there would be no clouds and no rain. All cloud droplets and rain drops, sleet and snow as well, need a particle on to which to form, and there is a lot to learn about aerosols, including sea spray. The composition of sea spray is linked to the composition of the seawater that emitted it. Changing what is in the seawater can likely change what is in the sea spray. A major control on seawater chemistry is biology. The ocean is teeming with microbes: microscopic organisms that grow on the gases in the atmosphere or by feeding on each other. Microbes create and release compounds throughout their lives and deaths, thus greatly influencing the chemical composition of seawater. Different microbes release different compounds. Also, different parts of the ocean are home to different microbes. By looking at the microbes present, we can get an idea of what compounds might be present in the seawater and in the sea spray. I am generating and collecting sea spray on board using a mini-Marine Aerosol Reference Tank, which gives me just the sea spray generated from the water inside and nothing else. Along with other researchers on board, I am also preparing samples to examine for microbes. I will collaborate with those other researchers to determine which microbes were present in the water I used to generate sea spray aerosol. We will also then look at what compounds are associated with those microbes. I will then examine the sea spray I have generated and collected on filters for those same compounds. If I find them in the sea spray, I can show one way that microbes influence the chemical composition of sea spray.

generating sea spray from water collected offshore California

The R/V Thomas G. Thompson

Posted by Matthew