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iStock

Plankton Make Clouds Brighter and the Earth Cooler

iStock
iStock

Plankton, the tiny organisms that drift through the ocean (plotting to take over the world, if SpongeBob Squarepants is to be believed), may play a vital role in keeping the Earth cool. A new study from the University of Washington and the Pacific Northwest National Laboratory finds that gases produced by plankton in the Southern Hemisphere create brighter clouds, reflecting sunlight.

The study, published in the journal Science Advances, found that clouds in the Southern Hemisphere are composed of smaller droplets in the summer, making them brighter than they would be otherwise. (Cloud reflectivity is based on both the amount of liquid they contain and the size of the droplets that liquid is spread across.)

A phytoplankton bloom off the coast of Alaska. Image Credit: NASA's Goddard Space Flight Center, Norman Kuring; USGS

Plankton double the concentration of water droplets in clouds in the summer, when phytoplankton bloom in the southern half of the world, according to the study. The tiny organisms produce gases like dimethyl sulfide that can seed cloud droplets, which form from aerosols. Caught up in sea spray, small particles of organic matter from plankton can also make their way into clouds, where they can absorb light. Over the course of the year, the increased brightness associated with these denser cloud droplets reflects an estimated 0.37 watts of solar energy per square foot of cloud. Meaning without plankton, the Earth would be even warmer.

Image Credit: Daniel McCoy / University of Washington

This adds to previous research showing that plankton are important climate mediators in the Southern Hemisphere. In the global north, however, their role is less understood, since there are more interfering aerosols from forests and pollution, among other factors. 

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Blue Water Ventures International
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Stones, Bones, and Wrecks
Gold Artifacts Discovered in 19th-Century Shipwreck That Was the ‘Titanic of Its Time’
Blue Water Ventures International
Blue Water Ventures International

On June 14, 1838, the steamship Pulaski was sailing off the coast of North Carolina, headed for Baltimore, when one of its boilers exploded, killing numerous passengers and causing colossal damage to the ship. It sank in less than an hour, taking two-thirds of its passengers with it. In January 2018, divers finally found the wreckage, and their latest expedition has brought back numerous new treasures, according to The Charlotte Observer, including a gold pocket watch that stopped just a few minutes after the boiler reportedly blew up.

The Pulaski disaster, which the Observer refers to as “the Titanic of its time,” was notable not just for its high death toll, but for whom it was carrying when it went down. The luxury steamship’s wealthy passengers included former New York Congressman William Rochester and prominent Savannah banker and businessman Gazaway Bugg Lamar, then one of the richest men in the region. At the time, the North Carolina Standard called the sinking “the most painful catastrophe that has ever occurred upon the American coast.”

An engraving showing the 'Pulaski' exploding
An 1848 illustration of the Pulaski explosion
Charles Ellms, Wikimedia Commons // Public Domain

Divers from Blue Water Ventures International and Endurance Exploration Group (which owns the rights to the site) have located a number of artifacts that support the belief that the wreck they found is, in fact, what’s left of the Pulaski.

While they have yet to find the engraved ship’s bell (the main object used to authenticate a wreck), divers identified a few artifacts engraved with the name Pulaski, as well as numerous coins that were all produced prior to 1838. The 150 gold and silver coins discovered thus far are worth hundreds of thousands of dollars today. They’ve also discovered silverware, keys, thimbles, and the ship's anchor.

A close-up of the gold pocket watch
Blue Water Ventures International

And in their most recent expedition, the divers found a unique gold watch that further supports the claim that this ship is the Pulaski. The hands of the engraved solid gold pocket watch on a gold chain—a piece only the wealthiest of men could afford—are stopped at 11:05, just five minutes after the boiler reportedly exploded.

The excavation of the remains of the ship will hopefully illuminate more of its story. Already, it has changed what we know about the ship’s final night: The wreck was discovered 40 miles off the North Carolina coast, a bit farther than the 30 miles estimated in initial newspaper reports of the disaster.

The investigators hope to eventually find evidence that will allow them to pinpoint why the deadly explosion occurred. While such explosions weren’t rare for steamships at the time, the crew may have pushed the ship beyond its limits in an attempt to reach its destination faster, causing the boiler to burst. Expeditions to the wreckage are ongoing.

[h/t The Charlotte Observer]

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Eater, YouTube
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Food
Watch How Ocean Water Gets Turned Into Table-Ready Salt
Eater, YouTube
Eater, YouTube

Turning the sea into edible salt is more time-consuming and laborious than you might think, as this video from Eater's series How to Make It taught us.

Eater's video team and chef Katie Pickens learned all about salt from Amagansett Sea Salt, a company that hand-harvests salt from the coast of Long Island. Pickens and Steve Judelson, her salt guide from Amagansett, collected 100 gallons of ocean water, using buckets to haul it in from the shallows.

Then, they drove it to the Amangansett facilities to filter and dry it. The salty water must be filtered several times to rid it of sediment and other floating objects and organisms you might not want to add to your food. But not all of the algae and plankton in the water get eliminated—some of that stuff actually improves the salt's taste. “That’s where a lot of the flavor comes from,” Judelson says.

Next, the filtered salt water is laid out to dry on long, covered beds in a field. In the summer, it takes about three weeks for the salt to crystalize and be ready to harvest, while in the winter, it might take as long as three months.

Watch the magic in the video below.

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