Q. With reference to Heatwaves in India, consider the following statements:
1.The threshold of maximum temperature for the declaration of a heatwave is lower for plains than hilly regions.
2.A heatwave occurs due to the movement of high atmospheric pressure into an area.
Which of the statements given above is/are correct?
Answer: B
Notes:
- Statement 1 is incorrect:Quantitatively, Heatwave is defined based on the temperature thresholds over a region in terms of actual temperature or its departure from normal. For instance, Heatwave will be declared if the maximum temperature of a station reaches at least 40 °C or more for plains and at least 30 °C or more for Hilly regions.
- Statement 2 is correct: A heatwave occurs due to movement of high atmospheric pressure into an area and lasts for two more days. In such a condition, air from the upper levels of our atmosphere is pulled towards the ground. It then gets compressed and triggers a rise in temperatures. The high pressure makes it difficult for other weather systems to move into the area. Movement of winds therefore becomes non-existent. The high-pressure system also bars clouds from entering the region and sunlight can further heat the system.
Source: Article
