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Factors contributing to the formation of cyclones

Context:

5. This article discusses the impact of ocean warming on cyclone forecasts.

Introduction:

5. The Arabian Sea is experiencing increased heating due to global warming, leading to the formation of stronger cyclones like Biparjoy.
5. The IMD forecast for Biparjoy initially indicated that it would not make landfall in Gujarat but later changed to predict its impact on India four days before it hit.
5. In contrast, the recent cyclone Mocha in the Bay of Bengal followed the trajectory predicted by the IMD several days in advance.
5. The India Meteorological Department (IMD) has a higher accuracy in forecasting cyclones originating in the Bay of Bengal compared to those in the Arabian Sea.
5. Cyclones in the Bay of Bengal are better understood due to their higher frequency, while Arabian Sea cyclones have historically been fewer and less predictable.

Warming Oceans and Cyclone Formation:

5. Accurate forecasting of cyclones is crucial for timely and effective disaster preparedness and response. However, the warming of the oceans, primarily driven by climate change, has presented new challenges in predicting cyclones in the Arabian Sea.
5. The Arabian Sea’s cyclones are largely influenced by the sea surface temperatures (SSTs) in the region. Warmer ocean temperatures provide the necessary fuel for cyclone formation and intensification.
5. As the oceans warm due to climate change, the energy available for cyclone development increases, leading to more frequent and potentially stronger cyclones. This phenomenon has been observed in recent years, with a notable increase in cyclone activity in the Arabian Sea.
5. Ocean temperatures play a crucial role in forecasting cyclones. Accurate measurements of SSTs allow meteorologists to identify favourable conditions for cyclone development and track their path.
5. However, as the oceans warm, the existing forecasting models may struggle to accurately capture the changing dynamics. Rising temperatures can lead to the formation of unexpected cyclones, alteration in their tracks, and changes in their intensity.
5. While prediction models capture the heat within ocean layers, they often fail to fully capture the wind component, known as steering winds, which influences the direction and recurving of cyclones.
5. The Arabian Sea has a unique characteristic with a deeper layer of warm water, up to 40 meters, compared to the Bay of Bengal. These subsurface values are often not accounted for in prediction models, leading to inaccurate forecasts of cyclone strength and speed in advance.

Increased Variability and Uncertainty:

5. The warming oceans contribute to increased variability and uncertainty in cyclone forecasting.
5. Higher SSTs create an environment with greater moisture availability, which can result in the rapid intensification of cyclones.
5. This rapid intensification, combined with unpredictable atmospheric conditions, makes it challenging to anticipate cyclone behaviour accurately.
5. Consequently, the forecasting window for predicting cyclone tracks and landfall becomes narrower, reducing the lead time for effective evacuation and disaster preparedness.