Q. Consider the following statements:
1.The India Meteorological Department (IMD) declares a heat wave if the maximum temperature of a weather station reaches at least 40 degrees C in the plains and at least 30 degrees C in hilly regions.
2.The wet bulb temperature is the highest temperature to which a surface can be cooled by water evaporating from it.
Which of the statement(s) given above is/are correct?
Explanation –
Statement 1 is correct. The India Meteorological Department (IMD) has specific criteria for declaring a heat wave in different regions of the country. In the plains, a heat wave is declared when the maximum temperature reaches at least 40 degrees Celsius, while in hilly regions, it is declared when the maximum temperature reaches at least 30 degrees Celsius. The IMD can also declare a heat wave if the actual maximum temperature crosses 45 degrees C, and a ‘severe heat wave’ if it crosses 47 degrees C.
Statement 2 is incorrect. The wet bulb temperature is the lowest temperature to which air can be cooled by the evaporation of water into the air. It is a measure of the moisture levels in the atmosphere and takes into account both temperature and relative humidity, providing a more accurate representation of the actual felt temperature, especially during humid conditions.
Source: The Hindu
