Researchers have known for quite a while that microorganisms in the ocean can significantly affect the local weather but now, a new connection has been found between phytoplankton breakdown and cloud formation. This can lead to improved climate models and better weather prediction.

Waves splashing spread out organic components which can encourage cloud formation. Image via Wikipedia.

I just love mornings by the sea – the sun is starting to shine, the breeze is cooling you off, and the waves are splashing on in a monotonous and soothing movement. But there’s more than meets the eye in that water that the waves are splashing – scientists have proven that bacteria on the ocean’s surface can affect the molecular makeup of sea spray droplets.

Basically, bacteria break down phytoplankton, the ubiquitous photosynthesizing organisms that inhabit almost all oceans and seas. As they break it down, they release proteins, sugars and lipids which get trapped in water droplets, and these water droplets can be ejected into the atmosphere. Naturally, this raises the number of organic components in the atmosphere, which is important in cloud formation – several studies have attempted to link phytoplankton blooms with organic content in the atmosphere, but failed to do so conclusively. They then went to the lab to see exactly what the effects are.

They were especially interested by phytoplankton blooms, so that’s the condition they tried to recreate. They managed to bring some 13,000 liters (3,400 gallons) of California sea water into the lab, into a controlled ocean-atmosphere wave machine. Their first results showed that increased phytoplankton concentration did indeed lead to increased organic content, and that organic content controls and encourages cloud formation (to an extent).

“Sea spray aerosol (SSA) particles profoundly impact climate through their ability to scatter solar radiation and serve as seeds for cloud formation. The climate properties can change when sea salt particles become mixed with insoluble organic material formed in ocean regions with phytoplankton blooms. Currently, the extent to which SSA chemical composition and climate properties are altered by biological processes in the ocean is uncertain.”

The research also shows that the interactions between the oceanic aerosols, microorganisms and climate is much more complex than previously understood. It’s interactions like this one that makes climate modelling so complicate – the more interactions we can factor in, the more accurate the models get.

Here’s a very good video detailing the processes through which aerosols affect our climate:

Journal Reference: Xiaofei Wang  et al. Microbial Control of Sea Spray Aerosol Composition: A Tale of Two Blooms. DOI: 10.1021/acscentsci.5b00148