Grownup clouds forestall child clouds from being born – CNET

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The view from the DC-8 research aircraft flies through the marine boundary layer, the near-surface part of the atmosphere in which the ocean influences processes such as cloud formation.

Sam Hall

Shooting through the sky on a NASA plane, scientists discovered that about a third of fresh cloud seedlings that come from the ocean disappear into veteran clouds before giving birth to new ones. The disappearance will ultimately affect the cloud factory’s assembly lines and reduce the production of baby clouds that could one day help protect the planet.

And with the climate crisis in full swing, the earth may need all the clouds it can get.

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Typically, cloud production requires specific sulfur compounds that are released from plankton in the ocean. The emission occurs when hungry marine animals bite from these creatures and break their cell walls. But according to a study published Monday in the Proceedings of the National Academy of Sciences, this precious element encounters a roadblock while it is working to create small clouds – other clouds.

“It turns out that this history of cloud formation was really incomplete,” Tim Bertram, professor of chemistry at the University of Wisconsin-Madison and senior author of the new report, said in a statement.

Refining our knowledge of cloud formation, as aimed at by Bertram’s study, could help us better understand how changes in the ocean could affect the gigantic feather formations above us.

Clouds are critical to the Earth’s atmosphere – they not only paint the sky, they reflect excess sunlight and modulate how much precipitation we get. Because of this, such research across the board could help map the effects of climate change.

Bertram’s work goes back to the formation of the clouds.

Clouds are very similar to cotton candy, and not just because of their fluff. Just as the airy treat needs a stick to wrap, cloud particles need a strong anchor to build on. This is because they have to move from the evaporated water back into the liquid – the droplets have to cling to something.

The will-o’-the-wisps that glide around the earth do the trick with … plankton breath. Definitely not how cotton candy is made.

After these sea creatures release dimethyl sulfide, or DMS, which contains two carbon atoms and one sulfur atom, it turns into sulfuric acid in the air.

Sulfuric acid becomes a helpful tool that cloud particles cling to until they grow into the whimsical puffs we admire in the sky-blue sky. Essentially, blobs of the chemical are like cloud cores.

“For the past three or four years,” said Bertram, “we’ve been challenging parts of that story, both through laboratory and large-scale field experiments. Now we can better connect the dots between what is emitted from the ocean . ” and how you create those particles that promote cloud formation. “

Bertram points out how a group of scientists came to a new kind of knowledge about the formation of clouds a few years ago. Before the DMS made from plankton is completely converted into sulfuric acid, it reaches an intermediate stage called hydroperoxymethylthioformate or HPMTF. Back then, HPMTF was a completely new concept.

To really understand how HPMTF works in the sky, Bertram and other researchers chartered a giant DC-8 airplane owned by NASA to check it out for themselves.

“It’s a flying laboratory,” he said. “Essentially, all of the seats have been removed and very precise chemical instruments have been installed that allow the team to measure both the emitted molecules in the atmosphere and any chemical intermediates at very low concentrations.”

Surprisingly, they calculated that when the intermediate stage was reached, about 36% of the sulfur required for cloud formation was lost to clouds already in the atmosphere. When there were no other clouds near the sulfur cloud seedlings, the team saw baby clouds being born at normal speed.

“This loss of sulfur to the clouds reduces the rate of formation of small particles, that is, the rate of formation of the cloud cores themselves,” said Bertram. “The effects on cloud brightness and other properties must be investigated in the future.”

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