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Current Affairs July 25, 2023: El Niño, Indian Ocean Dipole, Granite on the Moon, PM-DevINE, MPLADS

{GS1 – Geo – PG – Climatology – 2023/07/25} El Niño and Indian Ocean Dipole (IOD)

  • Context (IE): The development of a positive Indian Ocean Dipole (IOD) limits the El Niño effect.

Normal Conditions

  • Warming and cooling of the Pacific is most important in terms of general atmospheric circulation.

Indian Ocean Dipole and El Nino

  • In a normal year,
    • A surface low-pressure system develops in the region of northern Australia and Indonesia (western equatorial Pacific), and
    • A high-pressure system develops near the coast of Peru and Ecuador (eastern equatorial Pacific).
  • As a result, the trade winds (easterlies) over the Pacific Ocean move strongly from east to west.
  • The easterly flow of the trade winds carries warm surface waters westward, bringing convective storms (thunderstorms) to Indonesia and coastal Australia.
  • Along the coast of Peru, cold bottom nutrient-rich water wells up to the surface to replace the warm water that is pulled to the west.

Walker Circulation During Normal Years

  • The Walker Circulation (Walker Cell) is caused by the pressure gradient force that results from a high-pressure system over the eastern Pacific and a low-pressure system over Indonesia.
  • It is indirectly related to upwelling off the coasts of Peru and Ecuador. This brings nutrient-rich cold water to the surface, increasing fishing stocks.

Graphical Representation of Walker Circulation Description automatically generated

  • Thermocline: a temperature gradient in a body of water that seperates layers at different temperatures.

El Niño

  • El Niño is the name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru.
  • In an El Niño year,
    • Air pressure drops over large areas of the central Pacific and along the coast of Peru, and
    • The regular low-pressure system is replaced by a weak high in the western Pacific (the southern oscillation).
  • The change in pressure pattern causes the trade winds to be reduced ― weak Walker Cell. Sometimes Walker Cell might even get reversed.
  • This reduction allows the equatorial counter-current (west to east current along calm doldrums) to accumulate warm ocean water along the coastlines of Peru and Ecuador, replacing the cool Peruvian current.

El Nino Conditions

  • The accumulation of warm water causes the thermocline to drop in the eastern part of the Pacific Ocean which cuts off the upwelling of cold deep ocean water along the coast of Peru.
  • Climatically, the development of an El Niño brings
    • Drought to the western Pacific (Indonesia and Northern Australia),
    • Rains and floods to the equatorial coast of South America, and
    • Strong convective storms and hurricanes to the central Pacific.
  • El Niño typically occurs around Christmas and usually lasts a few weeks to a few months.
  • Sometimes, an extremely warm event can develop that lasts for much more extended periods. For example, in the 1990s, strong El Niños developed in 1991 and lasted until 1995.

El Niño Southern Oscillation (ENSO)

  • The formation of an El Niño (circulation of surface ocean current) is linked with the Pacific Ocean circulation pattern known as the southern oscillation.
  • Southern Oscillation, in oceanography and climatology, is a coherent inter-annual fluctuation of atmospheric pressure over the tropical Indo-Pacific region.
  • El Niño and Southern Oscillation (SO) coincide most of the time hence their combination is called El Niño Southern Oscillation (ENSO).

Normal Conditions

  • Warm water accumulation in Western Pacific and cold water upwelling in Eastern Pacific.
  • Thunderstorms in the equatorial western Pacific and calm conditions in the equatorial eastern Pacific.

El Niño conditions

  • Equatorial counter-current flows along calm doldrums in the west-east direction.
  • Drought in Northern Australia and floods in Central America.

El Niño vs ENSO

  • Only El Niño Warm water in Eastern Pacific + Cold water in Western Pacific
  • Only SO Low-pressure over Eastern Pacific + High-pressure over Western Pacific
  • ENSO (Warm water in Eastern Pacific + Low-pressure over Eastern Pacific) + (Cold water in Western Pacific + High-pressure over Western Pacific)

El Niño Modoki

  • Conventional El Niño is characterised by strong anomalous warming in the eastern equatorial Pacific.
  • In contrast, El Niño Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific.
  • Such zonal gradients result in anomalous two-cell Walker Circulation over the tropical Pacific, with a wet region in the central Pacific and a dry region in the western and eastern Pacific.

El Nino Modoki

[UPSC Prelims 2010] A new type of El Niño called El Niño Modoki appeared in the news. In this context, consider the following statements:

  1. Normal El Niño forms in the Central Pacific Ocean whereas El Niño Modoki forms in the Eastern Pacific Ocean.
  2. Normal El Niño results in diminished hurricanes in the Atlantic Ocean, but El Niño Modoki results in a greater number of hurricanes with greater frequency.
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
  • Normal El Niño forms in the Eastern Pacific Ocean whereas El Niño Modoki forms in the Central Pacific Ocean. So, statement (1) is wrong.
  • Both El Niño and El Niño Modoki cause subsidence of air (anticyclonic conditions) in the Atlantic Ocean. Hence the rainfall and hurricane activity are suppressed. So (d) Neither 1 nor 2 is the answer.

Effects of El Niño and ENSO

  • El Niño/ENSO phenomenon is studied for long-range forecasting. In the years when the ENSO is strong, large-scale variations in weather occur over the world:
    • The arid west coast of South America receives heavy rainfall.
    • Heavy rains and floods occur in California, Ecuador, the Gulf of Mexico and China.
    • Severe droughts occur in Australia, Indonesia, India and southern Africa.
    • The warmer ocean surface waters devastate marine life off the coast of Peru and Ecuador. Fish catches are lower in the region than in the regular year.

Normal Conditions

  • Eastern Pacific == Coast of Peru and Ecuador == Cold Ocean Water == Good for Fishing.
  • Western Pacific == Indonesia and Australia == Warm Ocean Water == Plenty of rain.

El Niño/ENSO

  • Eastern Pacific == Coast of Peru & Ecuador == Warm Ocean Water == Fishing industry takes a hit.
  • Western Pacific == Indonesia and Australia == Cold Ocean Water == Drought.
[UPSC Mains 2014] Most of the unusual climatic happenings are explained as an outcome of the El-Niño effect. Do you agree?

Impact of El Niño on Indian Monsoons

  • El Niño/ENSO and Indian monsoon are inversely related. The most prominent droughts in India have been El Niño droughts, including the recent ones (2014-16).
  • El Niño directly impacts India’s agrarian economy as it tends to lower the production of summer crops such as rice, sugarcane, cotton and oilseeds. The ultimate impact is seen in the form of high inflation and low GDP growth, as agriculture contributes around 14 per cent to the Indian economy.

Impacts of El Nino and La Nina on Countries. Description automatically generated


  • The location of low-pressure and hence the rising limb of the Walker Cell over the Western Pacific is considered conducive to good monsoon rainfall in India.
  • The eastward shift of the rising limb of the Walker Cell from its normal position, such as in El Niño years, reduces monsoon rainfall in India.

Southern Oscillation Index and Indian Monsoons

  • Southern Oscillation Index (SOI) is used to measure the intensity of the Southern Oscillation. This is the difference in pressure between Tahiti in French Polynesia (Central Pacific), representing the Central Pacific Ocean and Port Darwin (in northern Australia), representing the Eastern Pacific Ocean.
  • The positive and negative values of the SOI, i.e. Tahiti minus the Port Darwin pressure, point towards good or bad rainfall in India.
Positive SOI Negative SOI
Tahiti (eastern Pacific) pressure is greater than that of Port Darwin (western Pacific) Reverse
Drought conditions in Eastern Pacific & good rainfall in Western Pacific Reverse
Good for Indian Monsoons Bad for Indian Monsoons

La Niña

  • After an El Niño event, weather conditions usually return to normal. However, in some years, the trade winds can become extremely strong, and an abnormal accumulation of cold water can occur in the central and eastern Pacific. This event is called a La Niña.

Effects of La Niña

  • Abnormally heavy monsoons in India.
  • Strong hurricane season in the Atlantic Ocean. (Hurricane Mitch (1998), the second-deadliest Atlantic hurricane on record (11,374 fatalities), developed during a strong La Niña year).
  • Drought over central North America.

[UPSC Prelims 2002] For short-term climatic predictions, which one of the following events, detected in the last decade, is associated with occasional weak monsoon rains in the Indian subcontinent?

  1. La Niña
  2. Movement of Jet Stream
  3. El Niño and Southern Oscillations
  4. Greenhouse effect at global level
  • La Niña enhances monsoon circulation. So (a) El Niño & SO is the answer.

[UPSC Prelims 2011] La Niña is suspected of having caused recent floods in Australia. How is La Niña different from El Niño?

  1. La Niña is characterised by unusually cold ocean temperature in the equatorial Indian Ocean whereas El Niño is characterised by unusually warm ocean temperature in the equatorial Pacific Ocean.
  2. El Niño has an adverse effect on the southwest monsoon of India, but La Niña has no effect on the monsoon climate.
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
  • La Niña is characterised by unusually warm ocean temperature in the equatorial Indian Ocean. It is associated with strong monsoon and above average rains and colder winters. So (d) Neither 1 nor 2 is the answer.

Indian Ocean Dipole Effect (Not Every El Niño Year Is The Same In India)

  • Not all El Niño/ENSO years led to a drought in India. For instance, 1997/98 was a strong El Niño year but no drought. On the other hand, a moderate El Niño in 2002 resulted in one of the worst droughts.
  • It was discovered that just like ENSO, a similar but less significant seesaw ocean-atmosphere system named the Indian Ocean Dipole (IOD/Indian Niño) was also at play.
  • IOD is defined by the difference in sea surface temperature between two areas in the equatorial region of the Indian Ocean (or poles, hence a dipole) ― a western pole in the Arabian Sea (western Indian Ocean) and an eastern pole in the eastern Indian Ocean south of Indonesia.


  • Similar to ENSO, the atmospheric component of the IOD was named Equatorial Indian Ocean Oscillation (EQUINOO) oscillating warm water and atmospheric pressure between the Bay of Bengal and the Arabian Sea.
  • During positive IOD, winds over the Indian Ocean blow east to west (from the Bay of Bengal towards the Arabian Sea). This results in the Arabian Sea being much warmer and the eastern Indian Ocean around Indonesia becoming colder and dry. During the negative IOD, the reverse makes Indonesia much warmer and rainier.
  • IOD starts to develop in April and is best devolved in October. It was demonstrated that a positive IOD index often negated the effect of ENSO, resulting in increased Monsoon rains in several ENSO years like 1983, 1994 and 1997.

The Role of ENSO in the Development of IOD

  • A positive IOD event often develops at times of an El Niño, while a negative IOD is sometimes associated with La Niña. During El Niño, the Pacific side of Indonesia is cooler than normal because of which the Indian Ocean side also gets cooler.

Impact of IOD On Cyclogenesis In the Northern Indian Ocean

  • Positive IOD (the Arabian Sea is warmer than the Bay of Bengal) results in more cyclones than usual in the Arabian Sea.
  • Negative IOD results in stronger than usual cyclogenesis in the Bay of Bengal. Cyclogenesis in the Arabian Sea is suppressed.

Positive Phase of Indian Dipole and Negative Phase of Indian Ocean Dipole. Description automatically generated

Neutral phase of the Indian Ocean Dipole

IOD Positive Phase IOD Negative Phase

[UPSC Prelims 2017] With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting the Indian monsoon, which of the following statements is/are correct?

  1. IOD phenomenon is characterised by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean.
  2. An IOD phenomenon can influence an El Niño’s impact on the monsoon.
Select the correct answer using the code given below:
  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2
  • IOD phenomenon is characterised by a difference in sea surface temperature between the tropical Western Indian Ocean and tropical Eastern Indian Ocean. So (b) 2 only is the answer.

{GS1 – Geo – PG – Geomorphology – 2023/07/25} Granite on the Moon

  • Context (WION | IT): A large granite formation has been discovered under a suspected volcanic feature on the moon’s surface called Compton-Belkovich.
  • The discovery of this batholith proves the existence of ancient volcanic activity on the lunar surface.
  • The granite formation was discovered using microwave frequency (which helps measure the heat below the surface) data gathered by two Chinese lunar orbiters, Chang’E-1 in 2010 and Chang’E-2 in 2012.
  • A batholith is a large, intrusive igneous rock formation that forms from the solidification of magma deep within the Earth’s and celestial bodies’ crust.
  • Batholiths typically comprise granite or granodiorite and can cover extensive areas.


  • Granite is a type of coarse to medium-grained intrusive igneous rock.
  • It is one of Earth’s crust‘s most abundant and widely distributed rocks.
  • It is formed deep within the Earth’s crust when magma slowly cools and solidifies over millions of years.
  • It is composed primarily of quartz, feldspar, and mica minerals.

More information on Volcanism > PMF IAS Physical Geography 1st Edition

{GS2 – MoDNER – 2023/07/25} PM-DevINE

  • Context (PIB): Prime Minister’s Development Initiative for North East Region (PM-DevINE) Scheme aims to address development gaps in the North East Region.
  • PM-DevINE scheme was announced as a 100% Central Sector Scheme in Budget 2022-23.
  • The scheme has an outlay of Rs. 6,600 crore for the four years from 2022-23 to 2025-26.
  • It is implemented by the Ministry of Development of North Eastern Region (DoNER) through the North Eastern Council (NEC).


  • Fund infrastructure convergently in the spirit of PM GatiShakti.
  • Support social development projects based on the felt needs of the North Eastern Region (NER).
  • Enable livelihood activities for youth and women.
  • Fill the development gaps in various sectors.

North Eastern Council (NEC)

  • It is the nodal agency of MoDNER overseeing the economic and social development of the NER.
  • It is a statutory advisory body constituted under the NEC Act 1971.
  • The headquarters of the council is situated in Shillong.


  1. The Governors and the Chief Ministers of the eight-member States.
  2. Chairman and three Members nominated by the President of India.


  • The council discusses any matter in which some or all of the States represented in the Council have a common interest and advises the Central and State governments concerned, particularly concerning:
    1. Any matter of common interest in economic and social planning.
    2. Any matter concerning inter-State Transport and Communications.
    3. Any matter relating to Power or Flood-control projects of common interest.

Ministry of Development of North Eastern Region (MoDNER)

  • It is responsible for the matters relating to the planning, execution and monitoring of development schemes and projects in the North Eastern Region.
  • This is the only Ministry with territorial jurisdiction.

North Eastern Region (NER)

  • It consists of eight states — Assam, AP, Manipur, Meghalaya, Mizoram, Nagaland, Tripura, and Sikkim.

North Eastern Region

  • It accounts for 7.9% of the total geographical area of the country.
  • It shares its boundary with four countries viz, China, Myanmar, Bhutan and Bangladesh.
  • The western side of the North East is connected to the eastern part of the Indian subcontinent by a narrow land corridor, sometimes referred to as the Siliguri Corridor or “Chicken’s Neck“.

{GS2 – MoSPI – 2023/07/25} MPLADS

  • Context (PIB): MPLADS funds can now be used to purchase IT systems and software for educational purposes (technical education) as per new MPLADS guidelines.
  • Members of Parliament Local Area Development Scheme (MPLADS) is a Central Sector Scheme formulated by the GoI in 1993-94.
  • MPLADS enables the members of parliament (MPs) to recommend developmental work in their constituencies, emphasising creating durable community assets based on locally felt needs such as drinking water, education, public health, sanitation, roads etc.
  • The Ministry of Statistics and Programme Implementation (MoSPI) is responsible for the policy formulation, release of funds and monitoring for the implementation of the Scheme.


  • The Annual MPLADS fund is Rs. 5 crore per MP constituency.
  • MPLADS funds are non-lapsable, either at the end of the Union Government or the District Authority.
  • The Ministry of Finance has revised the MPLADS rules to require MPs to deposit the interest accrued on these funds to the Consolidated Fund of India. This means that MPs will no longer be able to use this interest for development works.
  • MPs must recommend works yearly for SCs (15%) and STs (7.5%) areas out of the total amount.
  • Lok Sabha Members can recommend works within their Constituencies.
  • Elected Members of the Rajya Sabha can recommend works within the State of Election.
  • Nominated MPs of both the Rajya Sabha & Lok Sabha can recommend works anywhere in India.
  • Expenditure on specified items of non-durable nature is also permitted, as listed in the guidelines.

A Picture showing the Working of MPLADS.

Issues with MPLADS

Issue Description
Lack of transparency and accountability
  • MPs are not required to submit detailed reports on the utilization of funds.
  • There is no independent oversight body to monitor the scheme.
Ineffective targeting of funds
  • MPs are free to recommend any work in their constituencies, regardless of whether it is needed or beneficial to the local population. It led to the neglect of some areas, while others received disproportionate funding.
Lack of participation by local communities
  • The MPLADS scheme does not adequately involve local communities in the planning and implementing of development projects.
  • This results in resentment and distrust among some communities, who feel they have no say in how their resources are used.
Inadequate monitoring and evaluation
  • There is no systematic mechanism to track projects’ progress or assess their impact.
Lack of statutory backing
  • The MPLADS scheme is not backed by any legislation. This has made it difficult to enforce the rules and regulations governing the scheme.
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