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FORECASTING CYCLONES IN ARABIAN SEA

17th June, 2023 Geography

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Context:  Global warming has caused increased cyclone activity in the Arabian Sea, leading to the need for improved forecasting methods.

Details: The India Meteorological Department (IMD) has generally been accurate in forecasting cyclones in India. However, data suggests that forecasting the trajectory of cyclones originating in the Arabian Sea is more challenging than those in the Bay of Bengal. Global warming has led to increased cyclone activity in the Arabian Sea, necessitating improved forecasting methods.

Arabian Sea Cyclone Forecasting Challenges:

a) Time Delay in Forecasting: IMD takes more time to accurately forecast the trajectory of cyclones in the Arabian Sea compared to those in the Bay of Bengal.

b) Heating of the Arabian Sea: Global warming has caused the Arabian Sea to heat up more than average, leading to the formation of stronger cyclones like Biparjoy.

 Recent Example: The IMD initially predicted Biparjoy to move away from the Gujarat coast, but it changed its forecast four days before landfall.

Bay of Bengal Cyclone Forecasting Success:

  • Historically, cyclones in the Bay of Bengal have been more frequent, allowing for better understanding and prediction.
  • Cyclones like Mocha, Sitrang, Yaas, Mandous, and Gulab followed paths predicted by the IMD at least four or more days in advance.

Factors Influencing Arabian Sea Cyclone Forecasting:

a) Steering Winds and Heat: Steering winds in the upper atmosphere and heat within ocean layers influence cyclone direction, strength, and duration.

b) Challenges in Capturing Wind Patterns: IMD models sometimes struggle to fully capture the wind component, making it difficult to predict cyclone paths accurately.

c) Unique Factors in the Arabian Sea: Deeper warm water layers in the Arabian Sea, up to 40 meters, affect cyclone intensity and movement. These factors are often not well-captured in prediction models.

1.Improving Forecasting Methods:

  • Need for Incorporating Additional Factors: Computational resources should be used to incorporate factors such as ocean-atmospheric interactions into forecast models.
  • Importance of Subsurface Data: Subsurface values, particularly in the Arabian Sea, should be considered to accurately predict cyclone strength and speed.
  • Collaboration and International Models: The IMD incorporates inputs from Indian and international models to estimate cyclone tracks and intensities.

2.Increasing Arabian Sea Cyclone Activity:

  • A study highlights a 52% rise in Arabian Sea cyclones from 2001-2019 and an 8% decrease in Bay of Bengal cyclones.
  • Understanding and forecasting Arabian Sea cyclones is becoming increasingly important.

3.Conclusion:

  • While the IMD has generally been successful in forecasting cyclones in India, there are specific challenges when it comes to cyclones in the Arabian Sea.
  • Improving forecasting methods, incorporating additional factors, and considering unique characteristics of the Arabian Sea will enhance cyclone prediction accuracy and ensure better preparedness for potential landfall events.

PRACTICE QUESTION

Q) Discuss the importance of Early Warning System in Disaster Risk management, preparedness and mitigation. (200 words)

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