Eerie, milky-white patches in the ocean have been spotted in satellite images, but the cause of the white clouds remains a mystery to scientists.

The NASA Earth Observatory Image of the Day for January 23, 2023, shows these strange blotches of white in the waters off the Bahamas, taken in 2015.

This particular “whiting event”, as they are known, lasted for around two months before fading away.

whiting event nasa
White smudges in the ocean known as “whiting events” off the Bahamas, as seen from space. Scientists still aren’t sure what exactly causes these areas of concentrated calcium carbonate.
NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey.

Whiting events have been sighted for many years, but the exact reason for their occurrence still mystifies scientists. They have been seen in a variety of locations, ranging from waters off the Bahamas, in the Great Lakes, in the Persian Gulf, off the Florida coast, and even in Lake Kivu in central Africa.

Samples taken of the white areas of water during a whiting event has revealed that there is a high concentration of fine-grained calcium carbonate particles present, however, the exact cause of this is still unknown.

Research carried out by scientists at the University of South Florida used thousands of satellite images of the Bahama Banks collected by NASA’s Aqua satellite between 2003-2020 to model the patterns of whiting events in that area.

In a paper published in the journal Remote Sensing of Environment in 2023, co-author and oceanographer Chuanmin Hu describes their discovery that the area affected by whiting events had increased massively since the study began, rising from an average of about 25 square kilometers (9.7 square miles) in 2003 to as much as 300-350 square kilometers (115.8 to 135.1 square miles) in 2014 and 2015.

Additionally, the whiting event patches off the Bahamas varied hugely in size between 0.1 to 226 square kilometers (0.04 to 87.3 square miles), averaging in size at around 2.4 square km, or 0.93 square miles.

“I wish I could tell you why we saw that peak in activity, but we’re not there yet,” Hu told NASA Earth Observatory. “We do see some interesting relationships between environmental conditions, such as the pH, the salinity of water, and the behavior of winds and currents, but we can’t yet say what exact mechanical, biological, or chemical processes were responsible for that peak in activity. Ultimately, we need to do more field experiments and pair that with remote sensing research like this to better understand the formation processes.”

Theories about the reasons for these clumps of high calcium carbonate concentrations include the resuspension of sediment on the ocean floor by ocean currents, or increased phytoplankton activity somehow causing enormous amounts of the calcium carbonate to be released.

Other research into whiting events found increased levels of diatom family Thalassiosira in the waters of whiting events.

“It is possible that these diatoms play a key role in triggering whiting events because they can function as nucleation points or ‘seeds’ where calcium carbonate crystals grow, but more research is needed to prove this,” lead author Jacqueline Long told NASA Earth Observatory in 2018.

Despite these significant findings, the true cause for these mysterious white patches around the globe remains unknown.

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