Topics Covered: Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.
Hurricane Hanna hits Texas:
Hurricane Hanna has made landfall recently near Texas.
- It is expected to produce heavy rains across portions of southern Texas and northeastern Mexico.
What Are Hurricanes?
Hurricanes are large, swirling storms. They produce winds of 119 kilometers per hour (74 mph) or higher.
They form over warm ocean waters.
What Are the Parts of a Hurricane?
Eye: The eye is the “hole” at the center of the storm. Winds are light in this area. Skies are partly cloudy, and sometimes even clear.
Eye wall: The eye wall is a ring of thunderstorms. These storms swirl around the eye. The wall is where winds are strongest and rain is heaviest.
Rain bands: Bands of clouds and rain go far out from a hurricane’s eye wall. These bands stretch for hundreds of miles. They contain thunderstorms and sometimes tornadoes.
How Does a Storm Become a Hurricane?
A hurricane starts out as a tropical disturbance. This is an area over warm ocean waters where rain clouds are building.
- A tropical disturbance sometimes grows into a tropical depression. This is an area of rotating thunderstorms with winds of 62 km/hr (38 mph) or less.
- A tropical depression becomes a tropical storm if its winds reach 63 km/hr (39 mph).
- A tropical storm becomes a hurricane if its winds reach 119 km/hr (74 mph).
What Makes Hurricanes Form?
- Warm ocean waters provide the energy a storm needs to become a hurricane. Usually, the surface water temperature must be 26 degrees Celsius (79 degrees Fahrenheit) or higher for a hurricane to form.
- Winds that don’t change much in speed or direction as they go up in the sky. Winds that change a lot with height can rip storms apart.
- Factors responsible for the genesis of hurricanes.
- Naming of cyclones/hurricanes in various regions of the world.
- Why more cyclones in Eastern coast of India?
- What is Coriolis force?
- What is latent heat of condensation?
Discuss the factors responsible for the formation of tropical cyclones.
Sources: the Hindu.