Every June, the Indian subcontinent waits for a rainfall that arrives not as a single event but as a slow-moving system hundreds of kilometres wide. For centuries, farmers relied on folk signs, such as the flowering of certain trees or the behaviour of ants, to anticipate it. Today they are aided by satellites orbiting far above the earth, which observe the monsoon continuously rather than at intervals.
Geostationary satellites, which remain fixed above one region of the equator, photograph the same cloud fields every few minutes. By comparing successive images, meteorologists can track how a cloud mass thickens, drifts or breaks apart. Other satellites travel in lower polar orbits and carry instruments that measure the temperature and moisture of the atmosphere at different heights, information that no photograph can supply. Together, the two kinds of data feed computer models that estimate where heavy rain will fall.
Yet forecasts remain imperfect. The monsoon is shaped by ocean temperatures, mountain ranges and winds far beyond any single country's borders, and small errors in measurement can grow into large errors in prediction. Scientists therefore speak of probabilities rather than certainties. A forecast of 'eighty per cent chance of heavy rain' is not a failure if the day stays dry; it is an honest statement that, in about one case out of five, such conditions pass without a downpour. The value of the satellites lies not in removing uncertainty but in narrowing it, giving a coastal village hours to prepare instead of minutes.
Geostationary satellites, which remain fixed above one region of the equator, photograph the same cloud fields every few minutes. By comparing successive images, meteorologists can track how a cloud mass thickens, drifts or breaks apart. Other satellites travel in lower polar orbits and carry instruments that measure the temperature and moisture of the atmosphere at different heights, information that no photograph can supply. Together, the two kinds of data feed computer models that estimate where heavy rain will fall.
Yet forecasts remain imperfect. The monsoon is shaped by ocean temperatures, mountain ranges and winds far beyond any single country's borders, and small errors in measurement can grow into large errors in prediction. Scientists therefore speak of probabilities rather than certainties. A forecast of 'eighty per cent chance of heavy rain' is not a failure if the day stays dry; it is an honest statement that, in about one case out of five, such conditions pass without a downpour. The value of the satellites lies not in removing uncertainty but in narrowing it, giving a coastal village hours to prepare instead of minutes.
Question 1
Single correct option
What is the chief advantage of geostationary satellites mentioned in the passage?
- A. They measure the temperature at different heights
- B. They photograph the same region repeatedly every few minutes
- C. They fly lower than polar satellites
- D. They predict rainfall without computer models
Show answer and solution
Answer: (B) They photograph the same region repeatedly every few minutes
The passage states they remain fixed above one region and photograph the same cloud fields every few minutes. Measuring atmospheric temperature and moisture is attributed to polar-orbit satellites, and models are still needed for forecasts.
Question 2
Single correct option
Why are satellites in lower polar orbits also needed?
- A. They can see the monsoon more clearly in daylight
- B. They stay above a single region of the equator
- C. Their instruments supply temperature and moisture data that photographs cannot
- D. They are cheaper to launch than other satellites
Show answer and solution
Answer: (C) Their instruments supply temperature and moisture data that photographs cannot
The passage says polar satellites carry instruments measuring the atmosphere's temperature and moisture at different heights, 'information that no photograph can supply'. Staying fixed above the equator describes the geostationary type.
Question 3
Single correct option
According to the passage, scientists speak of probabilities because
- A. they do not trust satellite data
- B. farmers prefer numbers to words
- C. rain never follows a forecast
- D. small measurement errors can grow, and the monsoon is shaped by factors beyond any one country
Show answer and solution
Answer: (D) small measurement errors can grow, and the monsoon is shaped by factors beyond any one country
The third paragraph explains that ocean temperatures, mountains and winds lie beyond any border and that small errors can become large ones. Satellite data is valued, so distrust is not the reason.
Question 4
Single correct option
If a forecast gives an 80 per cent chance of heavy rain and the day stays dry, the passage implies that
- A. the forecast was not necessarily wrong
- B. the satellites had failed
- C. the forecast should be called dishonest
- D. the probability should have been 100 per cent
Show answer and solution
Answer: (A) the forecast was not necessarily wrong
The passage says such a forecast 'is not a failure' because in about one case out of five these conditions pass without a downpour. A dry day is therefore consistent with the stated probability.
Question 5
Single correct option
Which of the following best expresses the central idea of the passage?
- A. Satellites have made monsoon forecasts perfectly reliable
- B. Satellites narrow the uncertainty about the monsoon but cannot remove it
- C. Folk signs are more useful than modern instruments
- D. The monsoon cannot be studied from space
Show answer and solution
Answer: (B) Satellites narrow the uncertainty about the monsoon but cannot remove it
The last paragraph says the value of satellites lies 'not in removing uncertainty but in narrowing it'. This contradicts perfect reliability, and the passage never dismisses either satellites or space-based study.
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