Question

Which one of the following is the main reason why tropical cyclones rarely form over the Bay of Bengal during the summer monsoon season?

• A. Strong vertical wind shear
• B. Weak low-level relative vorticity
• C. Dry mid-troposphere
• D. Stable atmosphere

Hint:

Tropical cyclones require low vertical wind shear for optimal growth. In regions where wind shear is strong, cyclone development is typically suppressed.

Answer 1

The Correct Option is A

Tropical cyclones require favorable conditions for their formation, and vertical wind shear plays a crucial role in this. During the summer monsoon season, the Bay of Bengal typically experiences strong vertical wind shear, which is the main reason why tropical cyclones rarely form. Vertical wind shear refers to the change in wind speed and direction with height in the atmosphere. When the wind shear is strong, it disrupts the development of cyclonic systems by tilting the cyclone structure, preventing it from growing vertically and organizing into a strong tropical cyclone.
- Weak low-level relative vorticity (Option B) does not typically prevent cyclone formation; in fact, low-level vorticity is often needed for cyclonic development.
- Dry mid-troposphere (Option C) can inhibit tropical cyclone formation, but the primary limiting factor in the Bay of Bengal during the monsoon is the wind shear.
- Stable atmosphere (Option D) is also not the primary reason for rare cyclone formation in this region; while a stable atmosphere can inhibit some convection, the vertical wind shear is the primary factor.
Thus, the correct answer is (A) Strong vertical wind shear.