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Scientists Track Giant Ocean Vortex from Space 1 May 2019

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Scientists Track Giant Ocean Vortex from Space 1 May 2019 Scientists track giant ocean vortex from space 1 May 2019 very dry or very wet season compared to the average. "If we're about to connect these two, we might have an advantage in predicting the strength of the monsoon, which has huge socioeconomic impacts," said Bryce Melzer, a satellite oceanographer at Stennis Space Center in Mississippi and lead author of the new study in AGU's journal Geophysical Research Letters. A swirling sea Researchers have found a new way to use satellites to The Great Whirl is a huge whirlpool that forms monitor the Great Whirl, a massive whirlpool the size of every spring off the coast of Somalia, when winds Colorado that forms each year off the coast of East blowing across the Indian Ocean change direction Africa, shown here in a visualization of ocean currents in from west to east. English geographer Alexander the Indian Ocean. Credit: NASA Scientific Visualization Findlay first described the Great Whirl in his Studio. navigational directory for the Indian Ocean in 1866. According to Findlay, Lieutenant Taylor of the British Royal Navy described a "great whirl of Researchers have found a new way to use current" circulating clockwise at about the same satellites to monitor the Great Whirl, a massive latitude at Xaafuun, Somalia. "A very heavy whirlpool the size of Colorado that forms each year confused sea is created by this whirl," Findlay off the coast of East Africa, they report in a new wrote. The phenomenon became known as the study. Great Whirl, and sailors have long been wary of its strong waves and intense currents. Using 23 years of satellite data, the new findings show the Great Whirl is larger and longer-lived The Great Whirl starts to form in April but its than scientists previously thought. At its peak, the currents are deepest and strongest from June to giant whirlpool is, on average, 275,000 square September, during the official Indian monsoon kilometers (106,000 square miles) in area and season. A 2013 study using satellite data found that persists for about 200 days out of the year. Watch at its peak, the Whirl can grow to more than 500 an animation of the Great Whirl's evolution here. kilometers (300 miles) wide, making it wider than the Grand Canyon is long. More than being just a curiosity, the Great Whirl is closely connected to the monsoon that drives the The Great Whirl's circular currents extend hundreds rainy season in India. Monsoon rains fuel India's of meters downward and can go farther than 1 $2 trillion agricultural economy, but how much rain kilometer (0.6 miles) deep in some areas. The falls each year is notoriously difficult to forecast. If inertia it generates keeps the Whirl going well past researchers can use their new method to discern a the end of monsoon season in September, until pattern in the Great Whirl's formation, they might typically disappearing late in the fall. be able to better predict when India will have a 1 / 3 Studying the Whirl from afar months—in 1997. Scientists have been interested in the Great Whirl The researchers haven't yet found a pattern in the for years but have had difficulty studying it directly. Great Whirl that could help them predict the Indian Monitoring the Whirl requires many repeat monsoon. But they hope to also apply their method observations taken over a long period of time, but to tracking whirlpools in other areas. Whirlpools in rampant piracy off the Somali coast has prevented the Gulf of Mexico, for example, have very strong researchers from venturing near it or placing currents that could affect oil drilling operations in instruments in the ocean to observe it. the area. And because the Whirl is so large, it doesn't More information: B.A. Melzer et al, Evolution of behave the way smaller whirlpools do, and the Great Whirl Using an Altimetry?Based Eddy scientists have difficulty defining its boundaries. As Tracking Algorithm, Geophysical Research Letters a result, scientists don't fully understand how the (2019). DOI: 10.1029/2018GL081781 Whirl varies from year to year or exactly when it forms and when it disappears. Researchers have recently turned to satellites to Provided by American Geophysical Union see if they can monitor the Whirl from afar. In the new study, Melzer and his colleagues developed a new way to use satellite measurements of sea levels to better define the Great Whirl's boundaries and track it over time. The center of the Great Whirl actually rises higher than sea level and the currents spin around this "hill" of water. The researchers analyzed sea level satellite data from 1993-2015 to understand how the Whirl changes from year to year and what it looks like under different climate conditions. They found the Great Whirl is larger than previous thought. The average size of the Whirl over those 23 years was 275,000 square kilometers (106,000 square miles), making it larger than the state of Colorado. They also found there's a lot of variability in when the Great Whirl forms and how long it lasts. But on average, it lasts for 198 days—six and a half months—considerably longer than previous estimates of 166 and 140 days. The vast amount of inertia it generates keeps the Whirl spinning well past the official end of monsoon season in September. The researchers found the Whirl persists well into November and even December, and there were three years—2000, 2005, and 2010—when it persisted into the new year. The longest it lasted was 256 days—more than eight 2 / 3 APA citation: Scientists track giant ocean vortex from space (2019, May 1) retrieved 29 September 2021 from https://phys.org/news/2019-05-scientists-track-giant-ocean-vortex.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. 3 / 3 Powered by TCPDF (www.tcpdf.org).
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