Madden Julian Oscillation: MJO Meaning, UPSC Notes PDF

By meenakshi|Updated : July 15th, 2022

Madden Julian Oscillation is an oceanic atmospheric phenomenon. MJO or Madden Julian Oscillation is the disturbance of wind, clouds, and pressure that moves in the east direction with a speed equal to 4-8 m per second. It is responsible for changes in weather activities all around the globe. The weekly and monthly fluctuations in the tropical weather are a result of the Madden Julian Oscillation.

Madden Julian Oscillation UPSC stands an important role in the Indian Climate and is a major topic for the IAS exam. Below you will get to know everything about the Madden Julian Oscillation, Its phases, its importance, and how does Madden Julian Oscillation affect the Indian weather.

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What is Madden Julian Oscillation?

Madden Julian Oscillation is a geographical phenomenon that was discovered in the 1970s. It is responsible for the change in the weather all around the globe. This phenomenon is a traversing phenomenon and brings weekly and monthly weather changes in the tropical weather, most prominently over the Pacific Oceans and India.

  • It remains on the globe for an average of 30 to 60 days (sometimes it remains for 90 days).
  • The large cluster of clouds can range from 5000 to 10,000 Km in size and move towards the warm oceans from 60 65 degrees in the East to 150 180 degrees towards the East.

Madden Julian Oscillation is responsible for creating the cyclones. But, not all cyclones are born from the Madden Julian Oscillation. Some of them might result from a simple Rossby wave.

The Madden Julian Oscillation is created in the Indian Ocean and ends near the International Date Line where the wave is moist and this awareness leads to clouds all around.

Along with the most part, there is a dry part as well that comes back to its origin after moving all around the earth. This movement is called oscillation. The cycle keeps on repeating for 30 to 60 days. The Madden Julian Oscillation is said to occur at a preferred time, especially in the winter season.

Madden Julian Oscillation Latest News

A cyclone named Cyclone Asani was seen in the Bay of Bengal region. This cyclone became the reason for the rainfall on the Indian east coast. In the southern hemisphere, A twin Cyclone happened and it was named Cyclone Karim. The major reason behind these twin cyclones is known to be caused by Madden Julian Oscillation.

Phases of Madden Julian Oscillation

There are two phases of the Madden Julian Oscillation. In the case of the strong Madden Julian Oscillations, the earth gets divided into non-equal two halves enhanced and suppressed phases. These are explained as

  • Enhanced rainfall (or convective) phase: In the enhanced rainfall phase, the wind gets converged at the surface and the air is raised up in the atmosphere. In contrast to it this, the wind at the top is diverse. Because of this tension in the air motion, there is an increase in the condensation and ultimately leading to rainfall. In this phase, there is more rainfall, cloudiness, and even storminess.
  • Suppressed rainfall (or suppressed) phase: In this phase, the wind at the top is converged because of which the air is forced to sink from the high altitudes. This makes the atmosphere dry and warms it as well, thus suppressing the rainfall. There is dryness and more sunshine in Suppressed rainfall.

Madden Julian Oscillation and India Monsoon

The weather is impacted by MJO, EI Nino, and IOD (Indian Ocean Dipole). The MJO and EI Nino are responsible to affect the weather globally up to the mid-latitudes while Indian Ocean Dipole is restricted to India only.

Madden Julian Oscillation is a transverse phenomenon and is said to go through eight phases. MJO brings a good amount of rainfall over the Indian subcontinent when it is over the Indian ocean during the Monsoon season. In contrast to this, when MJO remains on the Pacific Ocean with a longer cycle, there is a lack of rainfall in the Indian Monsoon.

Periodicity of MJO

The periodicity of the is nearly 30 days. After the completion of 30 days, MJO results in Monsoon season with a good amount of rainfall. However, if it extends to 40 days, then there is a disturbance in the monsoon with low rainfall. Thus, the rainfall depends upon the MJO period. If MJO occurs for a shorter period then there is good rainfall otherwise it will lead to dry rainfall.

Madden Julian Oscillation UPSC

Madden Julian Oscillation UPSC comes under the Geography section of the UPSC Syllabus and holds an important section in the IAS Exam. Many questions have been asked in the UPSC Prelims and UPSC Mains exam.

To ensure a better understanding of the topics, you can download the Geography Books for UPSC and other NCERT Books for UPSC. You can also refer to the UPSC Study Material.

Madden Julian Oscillation Questions asked in UPSC

Madden Julian Oscillation UPSC is a prime topic for the IAS exam and various questions have been asked about this topic in the prelims and mains exam. Some of the questions asked are

Question: With reference to the Madden Julian Oscillation (MJO), consider the following statements:

  1. Shorter the cycle of MJO, the better the Indian Monsoon.
  2. The active phase of MJO is responsible for the precipitation and formation of tropical cyclones.

Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2

Answer: C. Both 1 and 2

Question: With reference to the Madden Julian Oscillation (MJO), consider the following statements

  1. Madden Julian Oscillation (MJO) can be defined as an eastward moving ‘pulse’ of clouds
  2. When it is over the Indian Ocean during the Monsoon season, it brings good rainfall over the Indian subcontinent.
  3. When it witnesses a longer cycle and stays over the Pacific Ocean, MJO brings bad news for the Indian Monsoon.

Which of the following statement(s) is/are correct about MJO

  1. Only 1
  2. Only 1 and 2
  3. Only 2 and 3
  4. All of the above

Answer: C. Only 2 and 3

Madden Julian Oscillation UPSC Notes PDF

Madden Julian Oscillation stands an important role in the IAS exam, so it is crucial that you cover the topic in detail.

Other Important UPSC Notes
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Abraham AccordGig Economy
Jet StreamsBiotechnology
Model Code of ConductInternational Energy Agency
Make in IndiaDholavira
Nagoya ProtocolPrompt Corrective Action
Suez CanalCoral Reefs
Sedition LawsSeparation of Powers
Atmanirbhar Bharat AbhiyanDeep Ocean Mission

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FAQs on Madden Julian Oscillation

  • Madden Julian Oscillation is a geographical phenomenon. It is defined as the disturbance of wind, clouds, and pressure. It moves in the east direction with a speed equal to 4 8 m per second and is responsible for changes in the weather around the pacific ocean and the Indian Ocean. 

  • Madden Julian Oscillation has two phases. These are- the enhanced rainfall (or convective) phase and Suppressed rainfall (or suppressed) phase.

  • MJO brings a good amount of rainfall over the Indian subcontinent when it is over the Indian ocean during the Monsoon season. If Madden Julian Oscillation periodicity is about 30 days, then it leads to heavy rainfall, but if MJO stays for more than 4o days, then it leads to a dry monsoon.

  • During Enhanced rainfall phase, the wind at the surface is converged while at the top, the wind is diverge. This disturbance rises the air motion that cause the increase in rainfall and condensation.

  • The pdf link for the topic is present here. You can download the Madden Julian Oscillation (MJO) UPSC Notes here.

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