. 24/7 Space News .
EARTH OBSERVATION
Scientists track giant ocean vortex from space
by Staff Writers
Washington DC (SPX) May 02, 2019

Researchers have found a new way to use satellites to monitor the Great Whirl, a massive whirlpool the size of Colorado that forms each year off the coast of East Africa, shown here in a visualization of ocean currents in the Indian Ocean.

Researchers have found a new way to use satellites to monitor the Great Whirl, a massive whirlpool the size of Colorado that forms each year off the coast of East Africa, they report in a new study.

Using 23 years of satellite data, the new findings show the Great Whirl is larger and longer-lived than scientists previously thought. At its peak, the giant whirlpool is, on average, 275,000 square kilometers (106,000 square miles) in area and persists for about 200 days out of the year. Watch an animation of the Great Whirl's evolution here.

More than being just a curiosity, the Great Whirl is closely connected to the monsoon that drives the rainy season in India. Monsoon rains fuel India's $2 trillion agricultural economy, but how much rain falls each year is notoriously difficult to forecast. If researchers can use their new method to discern a pattern in the Great Whirl's formation, they might be able to better predict when India will have a 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
The Great Whirl is a huge whirlpool that forms every spring off the coast of Somalia, when winds blowing across the Indian Ocean change direction from west to east. English geographer Alexander Findlay first described the Great Whirl in his navigational directory for the Indian Ocean in 1866.

According to Findlay, Lieutenant Taylor of the British Royal Navy described a "great whirl of current" circulating clockwise at about the same latitude at Xaafuun, Somalia. "A very heavy confused sea is created by this whirl," Findlay wrote. The phenomenon became known as the Great Whirl, and sailors have long been wary of its strong waves and intense currents.

The Great Whirl starts to form in April but its currents are deepest and strongest from June to September, during the official Indian monsoon season. A 2013 study using satellite data found that at its peak, the Whirl can grow to more than 500 kilometers (300 miles) wide, making it wider than the Grand Canyon is long.

The Great Whirl's circular currents extend hundreds of meters downward and can go farther than 1 kilometer (0.6 miles) deep in some areas. The inertia it generates keeps the Whirl going well past the end of monsoon season in September, until typically disappearing late in the fall.

Studying the Whirl from afar
Scientists have been interested in the Great Whirl for years but have had difficulty studying it directly. Monitoring the Whirl requires many repeat observations taken over a long period of time, but rampant piracy off the Somali coast has prevented researchers from venturing near it or placing instruments in the ocean to observe it.

And because the Whirl is so large, it doesn't behave the way smaller whirlpools do, and scientists have difficulty defining its boundaries. As a result, scientists don't fully understand how the Whirl varies from year to year or exactly when it forms and when it disappears.

Researchers have recently turned to satellites to 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 months - in 1997.

The researchers haven't yet found a pattern in the Great Whirl that could help them predict the Indian monsoon. But they hope to also apply their method to tracking whirlpools in other areas. Whirlpools in the Gulf of Mexico, for example, have very strong currents that could affect oil drilling operations in the area.

Research Report: "Evolution of the Great Whirl using an altimetry based eddy tracking algorithm"


Related Links
American Geophysical Union
Earth Observation News - Suppiliers, Technology and Application


Thanks for being there;
We need your help. The SpaceDaily news 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.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


EARTH OBSERVATION
What's behind the ground-breaking 3D habitat map of the Great Barrier Reef
Seefeld, Germany (SPX) May 01, 2019
International aquatic remote sensing company EOMAP will showcase its unique contribution to the world-first 3D habitat map of the Great Barrier Reef (GBR) at the International Forum on Satellite-Derived Bathymetry, SDB Day 2019, next month in Australia. The mapping project, '3D live habitats for the full extent of the Great Barrier Reef', will provide, for the first time, maps of the predicted coral types and underwater landscape for the more than 3,000 reefs within the 350,000 km2 of the GBR. ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

EARTH OBSERVATION
RSC Energia developed a one-orbit rendezvous profile

NASA Aids Testing of Boeing Deep Space Habitat Ground Prototype in Alabama

International Space Station suffers partial power loss, no danger to crew

Photobioreactor: oxygen and a source of nutrition for astronauts

EARTH OBSERVATION
NASA Says It Lost $700 Million in Failed Rocket Launches Due to Fraud Scheme

SLS Forward Join Set for Horizontal Assembly to Liquid Hydrogen Tank

SpaceX capsule was destroyed in 'anomaly': lawmaker

SpaceX Dragon cargo launch no earlier than May 3

EARTH OBSERVATION
ESA to Lose Member State Support if ExoMars Launch Postponed - Director-General

InSight lander captures audio of first likely 'quake' on Mars

All-woman engineering team heads to NASA Mars competition

A small step for China: Mars base for teens opens in desert

EARTH OBSERVATION
China's tracking ship Yuanwang-2 starts new mission after retirement

China to build moon station in 'about 10 years'

China to enhance international space cooperation

China opens Chang'e-6 for international payloads, asteroids next

EARTH OBSERVATION
Capella Space ramping up production with Blue Canyon Technologies' Attitude Control Systems

Satellite Constellations and Radio Astronomy

Iridium Awarded Gateway Support and Maintenance Contract by the U.S. Department of Defense

The Third Installment of the SpaceFund Reality (SFR) rating

EARTH OBSERVATION
Researchers discover surprising quantum effect in hard disk drive material

Flexible circuits for 3D printing

The first laser radio transmitter

Quantum gas turns supersolid

EARTH OBSERVATION
Rapid destruction of Earth-like atmospheres by young stars

Cosmic dust reveals new insights on the formation of solar system

Slime mold memorizes foreign substances by absorbing them

Necrophagy: A means of survival in the Dead Sea

EARTH OBSERVATION
Next-Generation NASA Instrument Advanced to Study the Atmospheres of Uranus and Neptune

Public Invited to Help Name Solar System's Largest Unnamed World

Europa Clipper High-Gain Antenna Undergoes Testing

Scientists to Conduct Largest-Ever Hubble Survey of the Kuiper Belt









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.