Which one of the following statements is not correct ?

Correct — option (4), The Monsoon Expedition (Monex) was organized under the joint auspices of the United States of America (U.S.A.) and India.

The stem asks for the statement that is not correct, and option (4) is it.

An Indian primary source settles it. In ISRO Scientific Note SN-08-79, 'The Monsoon Experiment MONEX' (September 1979), IMD's Director-General P. K. Das explains that MONEX was part of the Global Atmospheric Research Programme (GARP). His title also gives the right name: Experiment, not Expedition.

GARP, he writes, was organised by the World Meteorological Organization (WMO) and the International Council of Scientific Unions (ICSU). ISRO chairman S. Dhawan's preface calls MONEX an experiment 'organised by the international scientific community'.

Many countries took part. Among the major contributions to Summer MONEX, Das lists five research ships from the USSR, three civilian research aircraft from the USA, four research ships and one aircraft from India, and a research ship from France.

International MONEX management centres were set up in Kuala Lumpur and New Delhi. MONEX was not a joint US–India venture, so the incorrect statement is option (4): The Monsoon Expedition (Monex) was organized under the joint auspices of the United States of America (U.S.A.) and India.

The idea to remember: MONEX (1978–79) was an international GARP experiment under WMO and ICSU, with ships and aircraft from the USSR, the USA, India and France.

Why the others are wrong

• (1)
  The variability of rainfall at Chennai is more than that of Mumbai. — This statement is treated as correct, so it is not the answer. NCERT's Class IX text says 'Variability is high in the regions of low rainfall'.

  NCERT's Class XI text puts the west coast, where Mumbai lies, among areas above 200 cm, and east Tamil Nadu in the 100–200 cm band. Its 2006 edition lists the western coasts among areas with less than 25 per cent variability, and does not name the Tamil Nadu coast there.

• (2)
  The retreating monsoon causes some rains in the coastal areas of Tamil Nadu. — This statement is correct. NCERT's Class XI text says the retreating monsoon is dry in north India but brings rain to the eastern part of the Peninsula, where October and November are the rainiest months.

  It adds that a bulk of the Coromandel coast's rainfall comes from depressions and cyclones of this season. That makes it a true statement, not the incorrect one.

• (3)
  The western disturbances originate from the Mediterranean Sea. — This statement is correct. NCERT's Class XI text describes shallow cyclonic depressions originating over the east Mediterranean Sea, crossing West Asia, Iran, Afghanistan and Pakistan to reach north-western India.

  The Class IX text says these systems originate over the Mediterranean Sea and western Asia, and bring the winter rain locally called 'mahawat'.

Indian rainfall comes from several systems in different seasons. The south-west monsoon brings summer rain. In October and November, the retreating monsoon season brings rain to the eastern Peninsula. In winter, western disturbances bring rain and snow to the north-west.

Rainfall variability measures how much a place's rain departs from its average. NCERT's 2006 Class XI text computes it as the coefficient of variation: standard deviation divided by mean, times 100.

NCERT's Class IX text adds that variability is high in regions of low rainfall, and that areas of low rainfall are drought-prone.

Key facts

• ISRO Scientific Note SN-08-79 (1979): MONEX was a sub-programme of GARP's Global Weather Experiment, which began on 1 December 1978.
• The same note: GARP was organised by the WMO and the International Council of Scientific Unions (ICSU) in 1967.
• P. K. Das lists ships from the USSR, India and France and aircraft from the USA and India among Summer MONEX's major contributions (May–August 1979).
• NCERT (Class XI): in the retreating monsoon season, October and November are the rainiest months in the eastern Peninsula.
• NCERT (Class XI): western disturbances originate over the east Mediterranean Sea and gain moisture from the Caspian Sea and the Persian Gulf.

Common traps

• Assuming a big international experiment was a two-nation project: MONEX was part of GARP, under WMO and ICSU, with the USSR, the USA, India and France contributing.
• Reading 'retreating monsoon' as rainless everywhere: it is dry in north India but brings the eastern Peninsula its rainiest months.
• Equating heavy rain with variable rain: NCERT says variability is high where rainfall is low.

UnlockIAS will link similar questions from RAS Pre 2023 and 2013 here once those papers are published on this site.

• practice — not a real PYQ

  The Monsoon Experiment (MONEX) of 1978–79 was part of which programme?

  • (a)Global Atmospheric Research Programme
  • (b)Indian Ocean Experiment
  • (c)Tropical Rainfall Measuring Mission
  • (d)International Geophysical Year
  Answer(1) — P. K. Das's ISRO note describes MONEX as part of the Global Atmospheric Research Programme organised by the WMO and ICSU. Options (2), (3) and (4) are not the programme Das names for MONEX.
• practice — not a real PYQ

  According to NCERT, which are the rainiest months of the year in the eastern part of the Peninsula?

  • (a)June and July
  • (b)July and August
  • (c)October and November
  • (d)December and January
  Answer(3) — NCERT (Class XI) says the retreating monsoon brings rain to the eastern Peninsula, where October and November are the rainiest months. Options (1) and (2) fall in the south-west monsoon season, and option (4) falls in the cold season, when NCERT says most of the country is dry.