Article: Understanding the Fujiwhara Effect: Interactions Between Tropical Storms
The recent occurrence of typhoon Hinnamnor, or Super Typhoon Henry as it is known in the Philippines, and another tropical storm named Gardo prompted meteorologists to observe a fascinating weather phenomenon known as the Fujiwhara Effect. These events prompted an understanding of this intriguing meteorological event, its impacts and characteristics.
The Fujiwhara Effect: An Overview
The phenomenon in question, the Fujiwhara Effect, is identified by the interaction between tropical storms formed around the same time within the same ocean region. The centres, also known as the eyes of these storms, are usually within a distance of less than 1,400 km from each other. The intensity of these storms can vary greatly, ranging from a wind speed that classifies the storm as a depression (less than 63 km per hour), to a super typhoon (wind speed exceeding 209 km per hour).
This dynamic interaction could potentially lead to alterations in both the track and intensity of either, or both, storm systems. In rare circumstances, when storm systems are of comparable size and intensity, they could merge together, resulting in one bigger storm.
Understanding Different Types of Fujiwhara Effects
The Fujiwhara Effect can manifest itself in various ways, including the following:
Elastic Interaction: In this scenario, the direction of motion of the storms changes. This is the most common case and the ones that are more challenging to assess, requiring closer examination.
Partial Straining Out: This type of interaction sees a portion of the smaller storm being lost to the atmosphere.
Complete Straining Out: In this case, the smaller storm is entirely absorbed into the atmosphere. This is not observed for storms of equal strength.
Partial Merger: This interaction results in the smaller storm merging into the more significant one.
Complete Merger: In this situation, a full merger occurs between two storms of similar strength.
UPSC Civil Services Examination Explanation
In the 2020 UPSC Civil Services Examination, a question around the topic of storm systems was asked. The question was related to the occurrence of Jet streams and the characteristics of cyclones. The correct answer was option (c), indicating that not all cyclones form an eye.
A Jet Stream is a geostrophic wind blowing horizontally through the upper layers of the troposphere. They develop when air masses of varying temperatures meet. Jet Streams extend from 20° latitude to the poles in both hemispheres.
Cyclones are classified into two types, tropical cyclone and temperate cyclone. The ‘eye’ is the calm centre of a tropical cyclone with no rainfall, whereas temperate cyclones do not have an individual place where winds and rains are inactive; therefore, no eye is found.
Inside the eye of a tropical cyclone, the temperature is higher than 28°C and the dewpoint is less than 0°C. These warm and dry conditions are typical of extremely intense tropical cyclones.
Understanding patterns and characteristics of tropical storms and the Fujiwhara Effect is crucial for meteorologists and those affected by these weather events. It helps in providing accurate forecasts and warnings, allowing better preparedness and protection against potential damage caused by these powerful storm systems.