Context:
California (the USA) has been hit by two back-to-back Atmospheric River storms.
Atmospheric Rivers:
- Atmospheric Rivers – Relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics.
- Occur in – Extratropical North Pacific/Atlantic, South-eastern Pacific, and South Atlantic oceans
- Stages of Formation –
- Usually begin over tropical regions
- Warm temperatures cause ocean water to evaporate and rise into the atmosphere.
- Strong winds help to carry the water vapor through the atmosphere.
- As atmospheric rivers move over land, the water vapor rises up farther into the atmosphere.
- It then cools into water droplets, which fall as precipitation.
- Impacts –
- Intense atmospheric rivers can cause flooding, landslides, and mudslides.
- Lead to water supply disruption, and develop drought-like conditions.
- Significance – Weak systems can provide beneficial rain or snow
- Issue – Climate change is expected to increase the frequency and intensity of Atmospheric rivers
Pineapple Express:
- Pineapple Express – One well-known atmospheric river system
- Formed at – Hawaii
- Function – Picks up warm, moist air near Hawaii.
- Effect – Cause heavy rain and snow upon hitting land in the Western United States and Canada
Source: Times of India
Previous Year Question
The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation?
1. There are no clouds or water vapour in the lower stratosphere
2. There are no vertical winds in the lower stratosphere.
Which of the statements given above is/are correct in this context?
[UPSC Civil Service Exam – 2011 Prelims]
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (c)
