Consider the following Assertion A As an air parcel rises its temperature increases Reason R A risin...........

Geography Atmosphere

Consider the following:

Assertion (A): As an air parcel rises its temperature increases.

Reason (R): A rising air parcel absorbs heat from the surrounding and expands.

Select the code from following:

A and R are correct and R is correct reason of A

A and R are correct but R is not the Correct explanation of A.

A is correct but R is incorrect

Both A and R are incorrect

EXPLANATION:

BOTH STATEMENTS ARE INCORRECT.As a parcel ascends its pressure decreases with height.As there is no external heat exchange the process is called Adiabatic process.
As a parcel ascends its pressure decreases with height. Due to decrease of pressure there is a drop in temperature of the air parcel. As there is no external heat exchange the process called Adiabatic process.
As the temperature is reduced it is called adiabatic cooling. The point to be remembered is that it is different from environmental lapse rate. In case of environmental lapse rate the temperature decrease with increase in altitude but the air is not moving from its place. In case of Adiabatic cooling the air parcel itself is moving and there is a drop of temperature in air parcel. The rate of change of temperature is called Adiabatic rate of cooling.
Similarly as the parcel descends the pressure in parcel increases hence there is an increase in temperature. This is called Adiabatic heating.
Condition for instability: When the Adiabatic lapse rate of cooling is lower than the local lapse rate there is a condition for unstable air.