Current Affairs
Daily Bits

Dust winds in North India

  • Posted By
    10Pointer
  • Categories
    Geography
  • Published
    31st Mar, 2021

Context

Dust-laden winds are pushing the air quality into the poor category and increasing the concentration of coarse particles in the air.

What is the cause behind the winds?

  • Strong winds which are carrying dust to Delhi are coming from Rajasthan.
  • A cyclonic circulation over Rajasthan and the high temperatures due to heatwave over the past few days in northwest India are contributing to the dust winds

What are Cyclonic circulations?

  • Reason:These are the swirling motion of winds that are caused by a low-pressure area.
  • Cyclonic circulation normally pulls in warm moist air resulting in cloudiness which may result in rainfall.
  • Direction: In northern hemisphere, the cyclonic circulation rotates in a counter clock wise direction and in southern hemisphere it rotates in a clockwise direction.

Heat Wave

  • The World Meteorological Organization, defines a heat wave as 5 or more consecutive days of prolonged heat in which the daily maximum temperature is higher than the average maximum temperature by 5 °C (9 °F) or more.
    • A heatwave is a period of excessively hot weather accompanied by high humidity.
    • This is common in both Northern and Southern Hemispheres in summer as the jet stream goes with the sun.
  • Suitable condition: Heat waves form with strengthening high pressure and remain for around several days up to several weeks.
  • Change in Temperature: Heatwave is considered to occur 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.
    • Normal Heat Wave: Departure from normal is 4.50°C to 6.40°C
    • Severe Heat Wave: Departure from normal is  more than 6.40 degree C