1. It has a role to play in the stability and instability in the air.
2. It acts like a blanket allowing the earth to neither become too cold nor too hot.
Select the answer using the code given below :
Understanding Water Vapour's Role in the Atmosphere
The question asks about the functions of water vapour in the Earth's atmosphere. Let's examine each statement provided:
Statement 1: Water Vapour and Air Stability
Water vapour plays a significant role in determining the stability and instability in the air. Here's how:
- Density Changes: Water vapour is lighter (less dense) than dry air at the same temperature and pressure. Therefore, the amount of water vapour affects the overall density of air parcels.
- Latent Heat Release: When air containing water vapour rises and cools, the vapour can condense into liquid water droplets or ice crystals. This process, called condensation (or deposition), releases latent heat into the surrounding air. This released heat warms the air parcel, making it less dense and potentially causing it to rise further, leading to instability and cloud formation. Conversely, dry air lacks this heat source during cooling.
- Adiabatic Processes: The rate at which air cools as it rises (the adiabatic lapse rate) is different for moist and dry air. Saturated (moist) air cools more slowly than dry air because of the release of latent heat during condensation. This difference influences atmospheric stability.
Because of these effects, Statement 1 is correct.
Statement 2: Water Vapour as a Thermal Blanket
Water vapour acts like a blanket, helping to regulate the Earth's temperature. This is often referred to as the greenhouse effect.
- Absorption of Radiation: Water vapour is a potent greenhouse gas. It absorbs long-wave infrared radiation emitted by the Earth's surface.
- Re-emission of Radiation: After absorbing this energy, water vapour molecules re-emit it in all directions, including back towards the Earth's surface.
- Temperature Moderation: This trapping and re-emitting of heat prevents excessive cooling of the Earth's surface, especially at night or during winter. It helps maintain a relatively stable and habitable temperature range, ensuring the planet neither becomes too cold nor too hot overall.
Therefore, Statement 2 is also correct.
Conclusion on Water Vapour Statements
Both statements accurately describe crucial functions of water vapour in the atmosphere:
- It directly influences atmospheric stability and instability through density changes and latent heat release.
- It acts as a greenhouse gas, trapping heat and moderating the Earth's temperature.
Since both Statement 1 and Statement 2 are correct, the option including both is the right choice.
Similar Questions
- Arrange the following permanent gases present in the atmosphere in ascending order :
1. Helium
2. Hydrogen
3. Neon
4. Xenon
Select the answer using the code given below : Which of the following statements with reference to Surface inversion of temperature is/are correct?
1. It causes instability in the lower layers of the atmosphere.
2. This inversion commonly lasts for a few hours until the Sun comes up.Identify the cloud on the basis of the following characteristics:
I. They look like cotton wool.
II. They exist in patches and have flat base.
III. They are generally formed at a height of 4 to 7 km.
Important Questions from Atmosphere
In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index?
1. Carbon dioxide
2. Carbon monoxide
3. Nitrogen dioxide
4. Sulfur dioxide
5. Methane
Select the correct answer using the code given below.
A layer in the Earth's atmosphere called Ionosphere facilitates radio communication. Why?
1) The presence of ozone causes the reflection of radio waves to Earth.
2) Radio waves have a very long wavelength.
Which of the statements given above is/are correct?
The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation?
1) There are no clouds or water vapour in the lower stratosphere.
2) There are no vertical winds in the lower stratosphere.
Which of the statements given above is/are correct in this context?
The increasing amount of carbon dioxide in the air is slowly raising the temperature of the atmosphere, because it absorbs
Which one of the following is associated with the issue of control and phasing out of the use of ozone-depleting substances?
