FUJIWHARA EFFECT

The world is seeing a rise in cyclonic formations and in cases of cyclones merging to form mega cyclones, due to the warming of oceans.

The Fujiwhara effect was identified by Sakuhei Fujiwhara, a Japanese meteorologist whose first paper recognizing the Fujiwhara cases was published in 1921. The first known instance of the effect was in 1964 in the western Pacific Ocean when typhoons Marie and Kathy merged.

3. About Fujiwhara Effect

When two ocean storms form in the same region, their wind circulations start meeting each other at the mid and higher levels. This meeting of winds makes a bond between the two storms like a connecting limb through which they start influencing each other

4. Megacyclones

•  In an increasingly warming world, a dance and merger between two large enough tropical cyclones over any of the global oceans could lead to the formation of a mega cyclone, causing devastation along coastlines.
• The Fujiwhara Effect is any interaction between tropical storms formed around the same time in the same ocean region with their centres or eyes at a distance of less than 1,400 km, with the intensity that could vary between a depression (wind speed under 63 km per hour) and a super typhoon (wind speed over 209 km per hour).
• The interaction could lead to changes in the track and intensity of either or both storm systems. In rare cases, the two systems could merge, especially when they are of similar size and intensity, to form a bigger storm.

6. Formation of Cyclones

Hurricanes, cyclones, or typhoons are names of huge swirling wind circulations that form over warm ocean waters and are named depending on where they form. They are fuelled by heat, wind, and moisture and under the right conditions can gain significant strength and size. The big ones can have diameters of more than 1,000 km and wind speeds above 250 km per hour.

7. Fujiwhara Effects

• Super typhoon Hinnamnor, the strongest tropical cyclone of the year, was hurtling towards Taiwan from the western Pacific Ocean.
• Another tropical storm called Gardo was moving towards Hinnamnor from its southeast.
• As the two approached each other, they started a dance around the central line between them, showcasing a textbook example of what is known as the Fujiwhara Effect.
• After the dance, which lasted over a day, Hinnamnor devoured Gardo and eventually made landfall in South Korea, drowning seven people on September 7.
•  Another Megacyclone, two hurricanes, Danielle and Earl, formed one after the other in the North Atlantic Ocean, sparking fears of the Fujiwhara Effect
•  Another hurricane Kay also brewed in the eastern Pacific Ocean. In 2020 hurricanes Marco and Laura had formed back to back in the small region of the Gulf of Mexico and created a possibility of the Fujiwhara Effect

8. Fujiwhara Effect On Rise

10. Consequence Of the Fujiwhara Effect

• The occurrence of the Fujiwhara Effect makes cyclones more unpredictable due to their rapid intensification, carrying of more rain, and newer ways of moving over warming oceans.
• This is because each of the interactions between the two storm systems is unique and very difficult to capture with current climate models.
• In the case of typhoons Parma and Melor in 2009, it became extremely difficult for forecasters to track the movement or intensity of either of the storms, especially Parma, and provide people with an early warning because of the Fujiwhara interaction between the two storms.
• This resulted in large-scale devastation in the Philippines due to the weaker typhoon Parma gaining strength, changing track, and remaining stagnant over the Luzon region because of its interaction with the stronger typhoon Melor.
• The typhoon took multiple U-turns and made three landfalls over the Luzon region.
• In April 2021, a similar event happened in the Indian Ocean, when cyclone Seroja interacted with cyclone Odette just off the coast of Western Australia gaining strength and moving in uncharted ways
• Seroja had already caused flooding and landslides in Indonesia before moving toward Australia. After the interaction, Seroja maintained its intensity and caused per cent to 70 percent of buildings in the small resort town of Kalbarri in Australia.
• Seroja became a unique storm because the northwestern coast of Australia is prone to cyclones while the southwestern part hit by the cyclone does not get much storm activity.