Which of the following statements regarding tropical cyclones is/are correct? 1. These storms develop during the summer and autumn in every tropical ocean except the South Atlantic and eastern South Pacific Oceans. 2. Tropical cyclones that occur in the North Atlantic and eastern North Pacific Oceans are known as typhoons. 3. Tropical cyclones that occur in the Indian and South Pacific Oceans are called cyclones. Select the answer using the code given below:
Understanding Tropical Cyclones: Development and Regional Names
Tropical cyclones are intense low-pressure systems that form over warm tropical or subtropical oceans. They are characterized by strong winds circulating around a well-defined center, heavy rainfall, and often generate large waves and storm surges.
Let's carefully analyze each statement regarding tropical cyclones:
Analysis of Statements on Tropical Cyclones
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Statement 1: These storms develop during the summer and autumn in every tropical ocean except the South Atlantic and eastern South Pacific Oceans.
Tropical cyclones require warm sea surface temperatures (typically above $26.5^\circ\text{C}$) to form and sustain. They usually develop during the warmer seasons (summer and autumn) when ocean temperatures are highest. While they occur in most tropical ocean basins globally, the South Atlantic and the eastern South Pacific (west of South America) are notably less active or nearly devoid of tropical cyclones. This is primarily due to cooler ocean temperatures, unfavorable atmospheric conditions like high wind shear, and lack of atmospheric disturbances needed for formation in these regions. Therefore, this statement is correct.
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Statement 2: Tropical cyclones that occur in the North Atlantic and eastern North Pacific Oceans are known as typhoons.
The regional name for a tropical cyclone depends on the ocean basin where it forms. In the North Atlantic Ocean and the eastern North Pacific Ocean, tropical cyclones are known as hurricanes. The term typhoon is specifically used for tropical cyclones that form in the Northwest Pacific Ocean. Therefore, this statement is incorrect.
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Statement 3: Tropical cyclones that occur in the Indian and South Pacific Oceans are called cyclones.
In the North Indian Ocean (Bay of Bengal and Arabian Sea), these storms are called cyclones. In the South Pacific Ocean and the Southeast Indian Ocean, they are also commonly referred to as tropical cyclones or simply cyclones. While specific classifications exist (like tropical storm, severe tropical cyclone, etc.), the general term 'cyclone' is widely used for these systems in these regions. Therefore, this statement is correct.
Summary of Correct Statements
Based on the analysis:
- Statement 1 is correct because the South Atlantic and eastern South Pacific are exceptions to tropical cyclone development.
- Statement 2 is incorrect; tropical cyclones are called hurricanes in the North Atlantic and eastern North Pacific, not typhoons.
- Statement 3 is correct; they are called cyclones in the Indian and South Pacific Oceans.
Therefore, the correct statements are 1 and 3.
Conclusion
The statements that are correct are 1 and 3. This aligns with the option stating "1 and 3 only".
Tropical Cyclone Regional Names Revision Table
| Ocean Basin | Regional Name |
|---|---|
| North Atlantic Ocean | Hurricane |
| Eastern North Pacific Ocean | Hurricane |
| Northwest Pacific Ocean | Typhoon |
| North Indian Ocean | Cyclone |
| Southwest Indian Ocean | Tropical Cyclone |
| South Pacific Ocean (west of $160^\circ\text{E}$) | Tropical Cyclone |
| South Pacific Ocean (east of $160^\circ\text{E}$) | Tropical Cyclone |
Additional Information on Tropical Cyclone Formation
For a tropical cyclone to form and intensify, several conditions must be met:
- Warm Ocean Waters: Sea surface temperatures need to be at least $26.5^\circ\text{C}$ down to a depth of about 50 meters.
- Low Vertical Wind Shear: Wind shear is the change in wind speed or direction with height. Low shear is needed so that the thunderstorm activity associated with the developing storm can rise vertically.
- Atmospheric Instability: The atmosphere must be unstable, allowing for convection and thunderstorm development.
- High Humidity: High humidity is needed in the lower to mid-troposphere.
- Coriolis Effect: The system needs to be located far enough from the equator (typically at least 5 degrees latitude) for the Coriolis effect to initiate and maintain rotation. This is why tropical cyclones do not form right on the equator.
- Pre-existing Disturbance: A weather disturbance, such as a tropical wave or a low-pressure area, is needed to provide initial rotation.
The absence of suitable conditions, such as persistent high wind shear or cooler waters, explains why tropical cyclones are rare or absent in certain tropical regions like the South Atlantic and eastern South Pacific.
Similar Questions
Which of the following statements regarding clouds is/are correct?
1. Clouds are classified on the basis of altitude and their form.
2. According to altitude they are classified as High, Middle and Low clouds.
3. Stratus, Nimbostratus and Stratocumulus are high clouds.
Select the answer using the code given below:
Which of the following statements regarding humidity is/are correct?
1. It is a ratio between the actual amount of water vapour present in the atmosphere and the maximum amount it can hold at a given temperature.
2. When the relative humidity is high, more water evaporates from the skin.
3. The higher the air temperature lower the relative humidity of the air.
Select the answer using the code given below:
Which of the following statements regarding air temperature is/are correct?
1. Air temperature is measured at a standard height of 1.2 m ( 4.0 feet) above the ground surface.
2. The average rate of temperature decrease with height is termed as the environmental temperature lapse rate.
Select the answer using the code given below:
Which of the following statements regarding cyclones and anti-cyclones is/are correct?
1. In the Northern Hemisphere, cyclones rotate counter clockwise and anticyclones rotate clockwise.
2. Cyclones are often associated with cloudy or rainy weather, whereas anticyclones are often associated with fair weather.
3. In the Southern Hemisphere, the cyclonic spiral will be clockwise because the Coriolis force acts to the left.
Select the answer using the code given below:
Which of the following statements regarding the World Climate Types and their relation with Inter Tropical Convergence Zone (ITCZ) is/are correct?
1. Tropical Wet Climate is one of the world's rainiest due to the dominance of the ITCZ over it.
2. Tropical Savanna Climate experiences a distinctive alternation of wet and dry seasons, caused chiefly by the seasonal shift in latitude of the subtropical highs and ITCZ.
3. The Tropical Monsoonal Climate experiences heavy rainfall as a consequence of the nearness of the ITCZ for much of the year.
Select the answer using the code given below:
In which one of the following layers of the atmosphere all weather phenomenon occur?
- Snow, sleet and hail are the forms of
- Nisarga, Gati, Nivar, Tauktae and Yaas are names of
Consider the following statements about anticyclones :
1. Anticyclones are high pressure systems.
2. Air in the centre of the system must be subsiding.
3. Anticyclones are characterized by converging winds.
How many of the above statements is/are correct?
Which one of the following clouds is a rain-bearing cloud?
Important Questions from Climatology
In the context of climate, what is the full form of ITCZ?
With reference to the climatic conditions of the Prairies, which of the following statements is correct?
Land and sea breeze are caused due to _____________
Which island emerged in the Bay of Bengal in the after math of the Bhola cyclone in 1970?
In India, during October-November, with the apparent movement of the sun towards the south, the ______ over the northern plains becomes weaker.
