They detect in the Indian Ocean a new type of storm until now unknown

An atmospheric scientist has observed a new type of Meteorological phenomenon formed predominantly in the western Indian Ocean: called “Atmospheric lakes”With compact, slow-moving, moisture-rich storms, they carry water to the dry lowlands of the East African coast.

Unlike most storms – created by a vortex – this new type of storm creates lakes that are produced by large concentrations of water vapor dense enough to produce a large amount of precipitation.

Atmospheric rivers

These atmospheric lakes have been compared to the atmospheric rivers that we know of. Atmospheric rivers are long, narrow plumes of dense moisture. But unlike fast-flowing atmospheric rivers, slow-moving atmospheric lakes separate from the weather system that produces them as they move at a leisurely pace toward the shoreline. This is because Atmospheric lakes have been discovered in an equatorial location notorious for their almost negligible wind speeds.

“These bodies of vapor sometimes drift westward over the East African coast, bringing rain to that semi-arid area,” explains a summary of the research.

“In contrast to the rain-bearing ‘atmospheric rivers’ of steam, which are contiguous from source to shore in an instant, we call these disconnected and drifting bodies of water ‘atmospheric lakes.’

Brian Mapes, an atmospheric scientist at the University of Miami who has recently observed and described these unique storms, presented his findings at the AGU Fall 2021 Meeting.

Finding with satellite data

Mapes used five years of satellite data to detect 17 atmospheric lakes lasting more than six days in a five-year period and less than 10 degrees from the equator, at all stations. However, according to a statement from the American Geophysical Union, Atmospheric lakes can also occur further from the equator, sometimes turning into tropical cyclones.

At present, a new research team is assembling to conduct a comprehensive study of this unique phenomenon. Among the various questions that scientists are going to probe is why exactly these atmospheric lakes are disconnected from the patterns of the river lakes from which they arise.

“The winds that carry these things to shore are so tantalizingly, delicately close to zero [velocidad del viento], that everything could affect them ”, said Mapes. “That’s when you have to know if they are self-propelled or if they are driven by some large-scale wind patterns that can change with climate change,” he added.

The aspect of climate change is important, because if the increase in temperatures affects the formation and trajectory of atmospheric lakes, it could have Important implications for the eastern coast of Africa, a typically dry and rain-hungry region. (I)