El Nino is an abnormal warming of water (at least 0.5 degrees Celsius warmer than the long-term average) in the central and eastern tropical Pacific Ocean off the northern coast of South America every two to seven years.
In the case of a strong El Nino event as occurred in 2015-2016, anomalies can reach as high as 3°C, which is a record.
An El Nino year creates a miniature global-warming crisis, since the warm water spreading across the tropical Pacific releases a large amount of heat into the atmosphere.
An El Nino phenomenon usually has higher influence on the global climate during the second year of its development.
Climate records of El Nino go back millions of years, with evidence of the cycle found in ice cores, deep sea muds, corals, caves and tree rings.
There is also an opposite of an El Nino, called La Nina. This refers to times when waters of the tropical eastern Pacific are colder than normal and trade winds blow more strongly than usual. Typically, El Ninos occur more frequently than La Ninas.
La Nina events may last between one and three years, unlike El Nino, which usually lasts not more than a year.
Both phenomena tend to peak during the Northern Hemisphere winter (Dec-Jan-Feb).
During the past two decades (2000-2020), the La Nina years experienced almost double the number of intense cyclones compared to the El Nino years in North Indian Ocean region.
According to the World Meteorological Organization (WMO), the 2023-24 El Nino phenomenon, experienced globally, is one of the five strongest on record, though it was weaker than the 1997-98 and 2015-2016 events.
What causes an El Nino?
Scientists do not yet understand in detail what triggers an El Nino cycle.
Normally, due to the presence of cold Peru Current (Humbolt Current) along the coast of Peru (South America), there is high pressure area in the eastern Pacific Ocean along the Peru Coast.
Therefore, air moves from the eastern Pacific Ocean to the western Pacific Ocean where there is comparatively a low pressure.
Because of the warmer oceans this air gets lots of moisture due to evaporation on the way.
This warm moist air rises to high levels of the atmosphere in the western part of the Pacific Ocean and causes rainfall in Indonesia, eastern and northern Australia etc.
The rise of warm air finally results in its cooling in the upper atmosphere. A part of this air moves towards the eastern Pacific Ocean in the upper atmosphere and descends over the eastern Pacific Ocean and helps to sustain the higher pressure there and again moves towards the western Pacific Ocean.
This way we have a complete circulation of air between eastern and western Pacific Ocean. This circulation is called Walker Circulation.
During El Nino years, due the abnormal warming of water in the central and eastern tropical Pacific Ocean the high pressure area in the eastern Pacific Ocean weakens, thus the wind moving towards the east (called easterly wind) weakens or even reverses its direction.
Thus, there is less rainfall/drought in the western Pacific Ocean (Indonesia, eastern and northern Australia and nearby areas including India etc.) whereas due to the presence of warm water in the eastern Pacific Ocean near Peru cloud formation takes place which causes heavy rainfall/floods in the coastal Peru.
The atmospheric pressure in the eastern Pacific Ocean is measured at a place called Tahiti whereas the atmospheric pressure in the western Pacific Ocean is measured at a place called Darwin.
During normal years there is high pressure at Tahiti and low pressure at Darwin. This situation exactly reverses during El Nino years and this phenomenon is called Southern Oscillation.
Together, La Nina and El Nino are the “cold” (La Nina) and “warm” (El Nino) phases of the El Nino-Southern Oscillation (ENSO).
El Nino and Indian Monsoon
An analysis of rainfall records of the past 132 years has revealed that severe droughts in India have always been accompanied by El Nino events, but not all such weather conditions have led to the failure of monsoons.
The El Nino events in 1965, 1972, 1982 and 1987 were bad for India but the 1997 El Nino, despite being the strongest in the century, did not affect monsoons (Thus, strong El Nino events are not always associated with drought).
This led many experts to conclude that the link between monsoons and global weather event was wearing off. But the India Meteorological Department still takes into account El Nino for Monsoon forecasts.
How El Nino affects Indian Monsoon: Mechanism
As discussed above, rising and cooling of the warm moist air in the atmosphere in the western part of the Pacific Ocean in the upper atmosphere results in its division into at least two parts.
A part of this air moves towards the eastern Pacific Ocean in the upper atmosphere and descends over the eastern Pacific Ocean and helps to sustain the higher pressure there.
One part also descends near East Africa and aids the formation of the Mascarene High Pressure Zone.
This increases the difference between the high pressure in the south over Mascarene High Pressure zone and the low pressure in the Indian subcontinent. Thus, more moisture laden winds move towards the Indian Subcontinent.
During El Nino years, due the abnormal warming of water in the central and eastern tropical Pacific Ocean the high pressure area in the eastern Pacific Ocean weakens, thus the wind moving towards the east (called easterly wind) weakens or even reverses its direction.
Thus, less or no air descends near East Africa which results in the weakening of the Mascarene High Pressure Zone.
Location of warming
Researchers also believe that even the location of the warming in the Pacific may possibly have an influence on the monsoon.
Anomalous warming in the Central and East Pacific (Nino 3.4 region) could have a more profound adverse impact on the monsoon than when the warming shifts to the adjoining far east Pacific (Nino 3. region).
Note: A transition from a La Nina winter to an El Nino summer historically tends to produce a large monsoon deficit, on the order of 15%.
This means pre-monsoon and monsoon circulations tend to be weaker in an El Nino year.
Some research has indicated that the Indian Ocean dipole — that refers to the difference in temperatures between the surface waters in the west and east over the tropical Indian Ocean — could compensate for the negative effects of an El Nino.
Note: What is Normal Monsoon?
In case of monsoon season (June to September) rainfall over India as a whole, the long period average (LPA) is 87 cm (revised from 88 cm by IMD in April 2022) and standard deviation is 9cm (about 10% of mean value).
Therefore, when the rainfall averaged over the country as a whole is within ±10% from its long period average (LPA) or 90% to 110% of LPA, the rainfall is said to be “normal” and when the rainfall is <90% (>110%) of LPA, the rainfall is said to be “below (above) normal”.
Other effects of El Nino
The location of tropical storms shifts eastward during an El Nino because atmospheric moisture is fuel for thunderstorms, and the greatest amount of evaporation takes place above the ocean’s warmest water.
Record rainfall often strikes Peru, Chile and Ecuador during an El Nino year.
Fish catches offshore South America are typically lower than normal as during El Nino years, warm water persists and deepens, and cold, upwelling, nutrient rich water (which is present during normal years) fails to reach surface and the marine life migrates north and south, following colder water.
Strong El Ninos are also associated with above-average precipitation in the southern tier of the United States from California to the Atlantic coast.
Indonesia and northeastern South America tend toward drier-than-normal conditions.
Temperatures in Australia and Southeast Asia run hotter than average.
El Nino-caused drought and heatwaves can be widespread, affecting southern Africa, India, Southeast Asia, Australia, the Pacific Islands and the Canadian prairies.
In general, warm El Nino events are characterized by more tropical storms and hurricanes in the eastern Pacific and a decrease in the Atlantic, Gulf of Mexico and the Caribbean Sea.
An El Nino creates stronger wind-shear and more-stable air over the Atlantic, which makes it harder for hurricanes to form.
However, the warmer-than-average ocean temperatures boost eastern Pacific hurricanes, contributing to more-active tropical storm seasons.
Wind shear is defined as the amount of change in the wind’s direction or speed with increasing altitude.
The El Nino, along with global warming, had made 2016 as one of the warmest year on record.
The warming of the oceans is one of the major impacts of an El Nino event.
During an El Nino, the Pacific’s warmest surface waters occurs offshore of northwestern South America (as El Nino begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, this warm water pools near Indonesia and the Philippines).
Prevailing easterly trade winds weaken and even reverse direction during the El Nino climate phenomenon.
Miscellaneous: El Nino Modoki Vs La Nina Modoki
El Nino can further be classified into two types:
traditional El Nino which is characterized by strong anomalous warming in the eastern equatorial Pacific and
the El Nino Modoki that is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific.
La Nina Modoki is the counter part of El Nino Modoki and is characterised by colder central Pacific being flanked by warmer eastern and western Pacific.
ENSO Spring Barrier or Spring Predictability Barrier
The “ENSO spring barrier” or “spring predictability barrier” is often used to highlight the uncertainty in the outlook for ENSO (the El Niño – Southern Oscillation) in the first half of the year. It is more like a lull or a valley in ENSO forecasting accuracy.
After the spring, the ability of the models to predict becomes increasingly better.
This uncertainty is because of the tendency for the ENSO phase to shift as El Niño and La Nina episodes decay after their usual winter peak.
Triple-dip La Nina
During the period of 2020–2023, the La Nina effect occurred for its third consecutive northern hemisphere winter, making this a rare “triple-dip” event.
Other triple-dip La Nina’s recorded since 1950 spanned the years 1998-2001, 1973-1976, and 1954-1956.
GS Paper 2
BhashaNet Portal
News: Ministry of Electronics and Information Technology (MeitY) and National Internet Exchange of India (NIXI) recently announced the launch of the BhashaNet portal at the Universal Acceptance Day (March 28).
The theme of the event was “BhashaNet: Impetus Towards Universal Acceptance”,
Aim: The portal aims to advance digital inclusion and promote Universal Acceptance (UA) across India.
Key Features:
The portal will provide resources and information in multiple Indian languages, making it accessible to a wider audience.
Developers and businesses can access tools and guidelines to help them assess and improve the UA readiness of their applications and systems.
The portal will showcase best practices and case studies from organizations that have successfully implemented UA, serving as a source of inspiration and guidance for others.
Importance:
Universal Acceptance ensures that all domain names, including new top-level domains, Internationalized Domain Names and email addresses are treated equally and can be used by all Internet-enabled applications, devices, and systems.
BhashaNet portal aims to make .in (dot in) universally accepted domain.
The initiative aims to narrow the digital gap and foster greater inclusivity on the internet for individuals from diverse regions and backgrounds across India.
Vote-from-Home
News: The Election Commission has introduced vote-from-home for citizens aged 85 and above.
Eligibility:
Eligible voters include individuals aged 85 years and above.
Persons with disabilities (PwD) with a certified handicap of at least 40%.
Voting Procedure:
These voters can utilise Form 12D to inform the assistant returning officer concerned of their inability to physically attend the polling station to cast their vote.
Two polling officials, accompanied by a videographer, will visit eligible voters’ residences to facilitate the voting process.
Prior notification of the visit will be sent via SMS to the mobile numbers provided in the application.
Opting for Vote-from-Home: Once eligible voters opt for VfH, they forfeit the opportunity to cast their votes at polling stations on election day.
Ensuring Voter Participation: If a voter is not present during the initial visit, voting personnel will make subsequent attempts to facilitate voting at the given address.
However, failure to avail of the VfH opportunity will result in the forfeiture of the voter’s chance to cast a ballot.
Electoral Trusts
News: Two electoral trusts Paribartan Electoral Trust and Prudent Electoral Trust – disbursed corporate donations to political parties.
Electoral Trusts:
These are trusts set up by companies with the objective to distribute the contributions received from other companies and individuals to the political parties.
The companies which are registered under section 25 of the Companies Act, 1956 are only eligible to make an application for approval as an electoral trust, as per the ADR report.
The names of electoral trusts, currently, do not indicate the name of the company/group which set up the trusts.
Who can contribute to electoral trusts?
An individual who is a citizen of India
A company registered in India
An association of persons (Indian residents)
Who cannot contribute to electoral trusts?
An individual who is not a citizen of India
Other electoral trusts (approved under the Electoral Trusts Scheme)
Contributors without PAN
NRIs without a passport number
For administrative expenses, the electoral trusts are permitted to set aside a maximum of 5 percent of the total funds collected during a financial year.
The remaining 95 percent of total income of the trusts, including any surplus from the previous financial year, is required to be distributed to eligible political parties.
Laws/Rules governing the functioning of electoral trusts:
Rule 17CA of Income Tax Rules, 1962 inserted in 2013, lists the functions of electoral trusts approved by the Central Bureau of Direct Taxes (CBDT).
The Central Government, also launched ‘The Electoral Trusts Scheme, 2013, which specified the eligibility and procedure for registration as an electoral trust, apart from laying down the format for their registration.
Bima Sugam
News: The Insurance Regulatory and Development Authority of India has recently approved setting up of Bima Sugam.
Bima Sugam:
Bima Sugam shall be established by a not-for-profit company formed under Section 8 of the Companies Act, 2013.
E-commerce Platform for Insurance: Bima Sugam functions similarly to an e-commerce platform, facilitating the sale of insurance products from various companies.
Comprehensive Coverage: Bima Sugam will onboard all companies offering life and non-life insurance products, providing a wide range of options for policyholders.
End-to-End Digital Journey: From purchasing policies to renewals, claim settlements, portability, and grievance redressal, Bima Sugam aims to offer a seamless digital experience for policyholders.
Unified Platform Integration: Bima Sugam will integrate with government databases, insurers, intermediaries, and insurance repositories to fetch customer details, offer product information, and facilitate buying and servicing of insurance policies.
Single Interface for Stakeholders: Serving as a single interface, Bima Sugam enables customers, intermediaries, and agents to connect and transact across insurers (life, health, non-life), promoting transparency, efficiency, and collaboration throughout the insurance value chain.
Significance:
Bima Sugam aims to streamline the insurance purchasing process by eliminating paperwork traditionally associated with agents and brokers.
Bima Sugam consolidates all insurance policies—life, health, and non-life—into a single application or window, eliminating the need for customers to manage multiple policies separately.
Bima Sugam aims to enhance affordability by facilitating direct sales of insurance policies, potentially reducing commissions paid to intermediaries.
By consolidating insurance products on a single platform, Bima Sugam is expected to increase transparency and allow for easier comparison of different policies .
GS Paper 3
Earth Hour
News: “Earth Hour” was observed on March 23 from 8.30pm to 9.30pm (IST).
Earth Hour:
Earth Hour was famously started as a lights-out event in Sydney, Australia in 2007.
Earth Hour, a world initiative, is an annual event encouraging people to raise awareness about climate change and promote energy conservation.
It is observed annually on the last Saturday of March.
To observe the day, people around the world switch off their lights for an hour as a symbol of committing to the planet Earth.
The day was initiated and organised by the World Wildlife Fund (WWF), which aimed to encourage individuals worldwide to come forward to preserve energy.
World Wildlife Fund (WWF)
It is an international non-governmental organization working in the field of wildlife preservation, established in 1961.
WWF works around 6 areas: food, climate, freshwater, wildlife, forests & oceans.
Living Planet Report (every two years) is released by WWF.
Logo – Giant Panda
United Nation General Assembly (UNGA) resolution on Artificial Intelligence
News: The UN General Assembly recently adopted a landmark resolution on the promotion of “safe, secure and trustworthy” artificial intelligence (AI) systems.
It was co-sponsored by over 120 other Member States (including India).
Key Features:
Closing the Digital Divide: The resolution aims to bridge the digital gap between wealthy developed nations and less affluent developing countries, ensuring equitable representation in AI discussions.
Enhancing Technological Capacities: It seeks to equip developing nations with the necessary technology and capabilities to leverage AI’s benefits, including disease detection, flood prediction, agricultural assistance, and workforce development.
Urgency of Global Consensus: Acknowledging the swift advancement of AI, the resolution emphasizes the critical need for international agreement on the safety, security, and trustworthiness of AI systems.
Evolution of AI Governance: Recognizing the evolving nature of AI governance, the resolution emphasizes the necessity for ongoing discussions to explore various governance approaches for artificial intelligence systems.
Tuberculosis (TB)
News: World Tuberculosis (TB) Day is celebrated on March 24 annually to spread awareness around the deadly disease.
TB: Tuberculosis (TB) is a communicable disease that is a major cause of ill health and one of the leading causes of death worldwide.
Cause: TB is caused by the bacillus Mycobacterium tuberculosis, which is spread when people who are sick with TB expel bacteria into the air.
Symptoms: TB can be latent – bacteria present in the body but not causing any symptoms. Symptoms of TB can include cough, weight loss, fever, and night sweats.
Cure: It is curable with early diagnosis and treatment. TB can be treated with antibiotics, but need to complete full course so as to prevent bacteria from becoming drug resistant.
World Tuberculosis (TB) Day:
Theme : World Tuberculosis (TB) Day, 24 March 2024, continues with the theme “Yes! We can end TB”.
History: On March 24, 1882 Dr Robert Koch discovered bacteria that causes TB.
The first World TB Day was officially observed in 1983, and since then, it has become an annual event.
