With summer approaching, "sea and sun" might conjure up images of a beach trip. But for scientists, the interactions of the two have big implications for the climate and for the formation of tiny droplets, or aerosols, that lead to clouds.

In ACS Central Science, researchers demonstrate that sunlight can cause certain molecules at the ocean's surface to activate others, resulting in larger molecules that could affect the atmosphere.

Certain organic molecules become activated and react when they absorb sunlight. They often go through a reactive intermediate called a "radical," which initiates a chain reaction leading to the formation of more complex chemicals.

This "radical initiator" pathway is important for understanding which molecules at the sea surface end up in the atmosphere, where they seed clouds. Which molecules are found in the atmosphere on aerosols will determine whether they absorb or reflect sunlight, affecting the temperature of the planet. Until now, scientists had focused much of their attention on the hydroxyl radical, which reacts very efficiently in the atmosphere.

Rebecca Rapf, Veronica Vaida and colleagues at the University of Colorado propose that a class of compounds called a-keto acids can be photo-activated by sunlight and drive reactions with molecules that do not themselves absorb sunlight.

The researchers studied two different a-keto acids and showed that light caused the acid to react with several fatty acids and alcohols. These classes of molecules are commonly found near the ocean's surface, and they are ubiquitous in biology.

The authors explain that this sunlight-initiated chemistry could change the composition of the sea surface.

The new, larger molecules formed may add to aerosols, changing their properties and leading to interesting and previously unforeseen consequences to human health, visibility and climate.

Research paper

Related Links
American Chemical Society
Earth Observation News - Suppiliers, Technology and Application

Tweet

Thanks for being here; We need your help. The Space Media Network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceMediaNetwork Contributor $5 Billed Once credit card or paypal		SpaceMediaNetwork Monthly Supporter $5 Billed Monthly paypal only

NASA's world tour of the atmosphere reveals surprises along the way
Greenbelt MD (SPX) Apr 17, 2018
Two thirds of Earth's surface are covered by water - and two thirds of Earth's atmosphere reside over the oceans, far from land and the traditional ways that people measure the gases and pollutants that cycle through the air and around the globe. While satellites in space measuring the major gases can close some of that gap, it takes an aircraft to find out what's really happening in the chemistry of the air above the oceans. That's where NASA's Atmospheric Tomography (ATom) mission comes in. ... read more