07 Mar 2024 : The Hindu Editorial

Topic 1 : 2023 El Niño is among the strongest on record: WMO

Context

Continuing El Niño and above-normal sea-surface temperatures over global oceans are expected to lead to higher temperatures over most land areas in the next three months.

El Niño

• El Niño is the periodic warming of the ocean surface in the central and eastern tropical Pacific Ocean.
• It occurs every two to seven years on average and typically lasts nine to 12 months at a time.
•  It is associated with more rainfall in the Horn of Africa and the southern U.S. and dry and warm conditions in Southeast Asia, Australia, and southern Africa.
• It is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO).
• It occurs more frequently than La Nina.

The strongest on record

• The 2023-2024 El Niño has peaked as one of the five strongest on record and will continue to affect climate in the coming months despite a weakening trend, as said by the World Meteorological Organisation (WMO).
• The prevailing El Niño conditions have already fuelled record temperatures and extreme events worldwide, with 2023 being the warmest on record.
• Scientists closely tracking the development in India have said La Niña conditions setting in by June-August could mean monsoon rains will be better this year than they were in 2023.
• Ocean surface temperatures in the equatorial Pacific clearly reflect El Niño. But sea-surface temperatures in other parts of the globe have been persistently and unusually high for the past 10 months.
• Scientists say an El Niño typically has the greatest impact on the climate in the second year of its development — 2024 in this instance.
• The continuing, albeit weaker, El Niño and predicted above-normal sea-surface temperatures over much of the global oceans are expected to lead to above-normal temperatures over almost all land areas in the next three months.

Impact of El Niño

• El Niño events have a major impact on societies and economies.
• Accurate seasonal forecasts from the WMO community helped countries prepare in advance to try to limit the damage in climate sensitive sectors like agriculture, water resources and health.

ENSO and India

1. El Nino: Strong El Nino events contribute to weaker monsoons and even droughts in India Southeast Asia.
2. La Nina: The cold air occupies a larger part of India than the El Nino cold air. In the ‘La Nina year’, rainfall associated with the summer monsoon in Southeast Asia tends to be greater than normal, especially in northwest India and Bangladesh.

• This generally benefits the Indian economy, which depends on the monsoon for agriculture and industry.
• It usually brings in colder than normal winters in India.

Conclusion

Early warnings of weather and climate extremes associated with El Nino have saved countless lives.

Topic 2 : What makes ASML’s chip-making machine a scientific marvel?

Context

By continuously making semiconductor chips smaller, faster, and more efficient, technology has progressed from just four transistors in the first integrated circuit in 1948 to more than 19 billion in smartphone chips. The High NA EUV machine is the current cutting edge in making these chips,.

Semiconductors

• Computers denote data in bits — the famous 0s and 1s — using semiconductors.
• These are small physical devices that store these values and perform mathematical operations on them. The sum of all these operations is what allows the computer to compute.
• The world has powerful computers almost everywhere around us thanks to a technology called semiconductor lithography — the science of printing intricate circuits with extreme precision.
• There are machines that automate this process, at a cost of anywhere between ₹800 crore and ₹1,600 crore.
• Only one company, ASML, headquartered in the Netherlands, makes them, giving it an absolute monopoly in a market and rendering it the technology company with the highest market value in Europe.

High NA EUV machine

• It is as big as a double decker bus.
• This machine uses extreme ultraviolet (EUV) photolithography, a next-generation technology, to make the semiconductors.
• Here, simply speaking, the mould of the circuits of a transistor — a type of semiconductor — are transferred to a silicon wafer coated with a light-sensitive material called a photoresist.
• When light is shined on the photoresist, the mould solidifies and its gaps can be filled with wires to form the transistor.

Rayleigh scattering criterion

• The smallest feature size that can be moulded on the silicon wafer is governed by a physics principle called the Rayleigh scattering criterion.
• According to this criterion, the size of the feature to be projected on the wafer is proportional to the wavelength of light used and inversely proportional to the aperture of the lens that collects light before projecting it onto the wafer.
• The proportionality with the wavelength of light includes a factor called ‘k’.
• Its value depends on many factors, including the operating temperature and the chemical properties of the photoresist, but has a maximum value of 0.25.
• In the inverse proportionality, the aperture indicates the amount of light that can be collected and focused on the wafer: the greater the aperture, the smaller the feature size.
• In most cases, engineers have reduced the smallest size imprinted on the wafer by reducing the wavelength of the light shined on the photoresist.
• Just before EUV machines, chip-makers relied on deep UV light (193 nm wavelength) to project intricate patterns onto the wafers.

The machine’s value

• As such, ‘High NA EUV’ doesn’t represent a single achievement but a collection of multiple achievements, brought together to push the boundaries of computing just enough to create the next generation.
• Mankind’s future is being constantly reshaped by artificial intelligence, robots, intelligent automobiles, high-quality digital communication, powerful gadgets, and space exploration.
• These innovations are not only transforming the way humans live and work but also opening new possibilities that were once in the realm of science fiction.
• The fundamental enablers of these revolutions are semiconductor chips, which carry out the enormous numbers of calculations required to materialise these technologies.
• By continuously making these chips smaller, faster, and more efficient, technology has progressed from just four transistors in the first integrated circuit in 1948 to more than 19 billion in the chip we use in our smartphones.
• This innovation is driven by Moore’s law, which describes the expectation that the number of transistors on a microchip will double approximately every two years.

Conclusion

These machines underscore the fact that major technological breakthroughs can provide highly skilled jobs as well as strengthen a country’s standing geopolitically.