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
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