Day 64 – Q 1. What conditions are required for the formation of a Tropical Cyclone? How was the recent Titli cyclone different from the usual tropical cyclones?
1. What conditions are required for the formation of a Tropical Cyclone? How was the recent Titli cyclone different from the usual tropical cyclones?
A tropical cyclone is an intense low pressure area or a whirl in the atmosphere over tropical or sub-tropical waters, with organised convection (i.e. thunderstorm activity) and winds at low levels, circulating either anti-clockwise (in the northern hemisphere) or clockwise (in the southern hemisphere). From the centre of a cyclonic storm, pressure increases outwards. The amount of the pressure drop in the centre and the rate at which it increases outwards gives the intensity of the cyclones and the strength of winds.
Tropical cyclones require certain conditions for their formation. These are
- A source of warm, moist air derived from tropical oceans with sea surface temperature normally near to or in excess of 27 °C
- Winds near the ocean surface blowing from different directions converging and causing air to rise and storm clouds to form
- Winds which do not vary greatly with height – known as low wind shear. This allows the storm clouds to rise vertically to high levels;
- Presence of Coriolis force, provides energy to rotate or curve in anti-clockwise (in the northern hemisphere) or clockwise (in the southern hemisphere)
How Titli Cyclone is different from usual cyclones?
- Indian Meteorological Department declared Titli cyclone a rarest of the rare occurrence and categorised it as ‘very severe cyclone’.
- Wind speed of normal tropical cyclone ranges around 118-120 km per hour. But Wind speed of Titli Cyclone was around 150 km per hour, which is rare occurrence.
- Reoccurrence or re-emergence: Usually cyclones die after landfall. But Titli Cyclone reemerged again after landfall on Odisha coast.
- Turned in Northeastern direction: Usually cyclones die after landfall, but Titli took a Northeast turn and continued.
These are some of the reasons because of which Titli Cyclone has been declared as rare occurrence.
Frequency and severity of storms are increasing. It has been argued that Climate Change can be one of the reason behind it. Improved forecasting and precision of IMD helped to mitigate the losses to eastern coast of India.
Best Answer: P29