Rossby waves, also known as planetary waves, are a type of inertial wave naturally occurring in rotating fluids.
They were first identified by Carl-GustafArvidRossby. They are observed in the atmospheres and oceans of planets owing to the rotation of the planet.
AtmosphericRossby waves on Earth are giant meanders in high-altitude winds that have a major influence on weather.
These waves are associated with pressure systems and the jet stream.
OceanicRossby waves move along the thermocline: the boundary between the warm upper layer and the cold deeper part of the ocean.
What is El Niño& La Niña?& How does it affects India?
El Nino is typically known as the warm phase and La Nina is identified as the cold phase of ENSO. These deviations from the normal surface temperatures can potentially have a large-scale impact on the global weather conditions, and the monsoon climate of the Indian subcontinent also gets affected with these temperature fluctuations in the Pacific.
El Nino, characterised by a warming of surface temperatures in the Pacific Ocean, is associated with lower than normal monsoon rainfall in India.
El Nino affects the flow of moisture-bearing winds from the cooler oceans towards India, negatively impact the summer monsoon, which accounts for over 70% of annual rainfall.
El Nina is observed when the water temperature in the Eastern Pacific gets comparatively colder than normal, as a consequence of which, there is a strong high pressure over the eastern equatorial Pacific.
The difference in pressure between Eastern Pacific and Western Pacific/Asia causes a moisture-laden wind movement from East to West Pacific and Asia.
As a result, La Nina causes drought in the South American countries of Peru and Ecuador, heavy floods in Australia, high temperatures in Western Pacific, Indian Ocean, off the Somalian coast and a comparatively better monsoon rains in India.
Generally, El Nino and La Nina occur every 4 -5 years. El Nino is more frequent than La Nina.
What does study say?
Droughts in India have historically been associatedwith El Nino, an anomalouswarming of the equatorialPacific, but scientists fromBengaluru suggest other culprits too.
The study says thatnearly six out of 10 droughts,in non-El Nino years, that occurred during the Indiansummermonsoon season inthe past century may havebeen driven by atmosphericdisturbances from the NorthAtlantic region.
In an El Niño year, abnormally warm equatorial Pacific waters pull moistureladenclouds away from the subcontinent, but the IISc studyshows that in non-El Ninoyears, these droughts are aconsequence of a suddenand steep drop in rainfall inlate August.
It seems, the researchersnote, that winds in the upperatmosphere are interactingwith a deep cyclonic circulation above the abnormallycold North Atlantic waters.
The resulting wave of air currents, called a Rossby wave,curved down from the NorthAtlantic squeezed in by theTibetan plateau and hit thesubcontinent around mid-August, suppressing rainfall and throwing off the monsoon that was trying to recover from the June slump.The wave’s usual course is to go from west to east, but not towards the equator.
The Indian Ocean andPacific Ocean seem to be atthe forefront of all discussions surrounding Indianmonsoon droughts.
TropicalMeteorology, too plays animportant role in determining the monsoon’s performance and several other factors will have to beconsidered to develop a reliable model to forecast a potential shortfall in the absence of El Nino.
In 2014, India saw a 14%rainfall deficit — or a drought— that wasn’t linked to El Nino and before that in 1986and 1985. “The sheer size ofthe Pacific means that it influences global climate much more than the Atlantic orother oceans.”
Context: India and Uzbekistan planto cooperate on connectivity projects in Afghanistanand will participate in a trilateral dialogue with Iran,said the two sides after talksbetween Prime Minister Narendra Modi and UzbekistanPresident ShavkatMirziyoyev during a virtual summit.
Topic in syllabus: Prelims – Places in news | Mains – IR (GS-2)
Last year, the first joint military exercise between our armed forces took place.
Our joint efforts are also increasing in the areas of space and atomic energy.
India also confirmed theapproval of a $448 millionLine of Credit for four developmental projects in Uzbekistan in the areas of “roadconstruction, seweragetreatment and informationtechnology”.
The two sides signed a Dollar Credit Line Agreementbetween the Export-ImportBank of India and the Uzbekistan Government and several Memorandums of Understanding (MoUs)including in the areas of renewable energy and information technology on the sidelines of the meeting.
The leaders instructedtheir officials to FastTrackthe conclusion of the ongoing Joint Feasibility Study that will pave the way forcommencement of negotiations on a Preferential TradeAgreement.
The two leadersacknowledged that the current bilateral trade level ofabout US $285 million (2018) was far below the potential.
Location of Uzbekistan:
Context: Centre set to unveil ‘ambitious’PSE divestment policy: Bajaj – ‘Barring 14 public sector players, other strategic sector PSEs too to be privatised’
Topic in syllabus: Prelims – Places in news | Mains – IR (GS-2)
What is divestment?
Divestment is the process of selling subsidiary assets, investments, or divisions of a company in order to maximize the value of the parent company.
Divestment is effectively the opposite of an investment and is usually done when that subsidiary asset or division is not performing up to expectations.
Why government is Interested in divestment?
Following are the main objectives of disinvestment:
To reduce the financial burden on the Government.
To improve public finances.
To introduce, competition and market discipline.
To fund growth.
To encourage wider share of ownership.
To depoliticise non-essential services.
The decision to disinvest is mainly to reduce the fiscal burden and bridge the revenue shortfall of the government.
The key engine in achieving growth in India during post-independence was played by Public Sector Enterprises (PSE).
Disinvestment is a major source of resources for investment in infrastructure and social sectors. These resources can be used to pay off the past debt and lower the interest burden of the government.
Disinvestment helps to improve efficiency of such entities(PSEs).
Examples related to Ethics (GS-4)
Tension gripped Sirukudalvillage in Perambalur district of Tamil Nadu after three minor boys belonging to the ScheduledCastes were forced to remove their excreta from anopen ground allegedly bysome caste Hindus. (Against Empathy, Tolerance and Compassion towards the weaker sections. | India society- GS1)
There would be no end to corruption unless people changed their way of thinking, Justice Sanjay KishanKaul stated in the Supreme Court and dismissed as withdrawn a plea seeking stringent punishment for corruption and money laundering.(Probity in Governance – Challenges of Corruption)
In TN, 100 kg gold missing from CBI custody, HC orders police probe (Probity in Governance – Challenges of Corruption)|Our Prestige will decrease if we are investigated by local policemen, says CBI (Case study)
Important news in short
India’s industrial output grewat the fastest pace in eightmonths in October 2020 at3.6%, with consumer durables production surpassing levels last seen prior to the COVID19 pandemic, as perquick estimates from the National Statistical Office (NSO).
A paper released by the Pranab Mukherjee Foundation(PMF) on the eve of the latePresident’s birth anniversarysuggested that thenext delimitation exerciseshould be a twostep process:first a Delimitation Commission should be set up to redraw boundaries of constituencies on the basis of the2031 Census and then a StateReorganisation Act be passedto split States into smallerones.
In the midst of conflicts in the last three decades, global financial crisis and mushrooming of many multilateral organisations, China’s rise has been one of the most defining moments of the 21st century, Chief of Defence Staff (CDS) Gen. BipinRawat stated.
Environment Minister Prakash Javadekar said that India was the only major G20country that was on track towards keeping to its nationally determined commitmentsto halt runaway global warming. It had achieved 21% of itsemissions intensity reduction target as a proportion ofits GDP in line with its pledgeto a 3335% reduction by2030, he said.
In 2015, ahead of the UnitedNations’ significant climateconference in Paris, India announced three major voluntary commitments called the Nationally Determined Contributions (NDC):
improvingthe emissions intensity of itsGDP by 33–35% by 2030 over2005 levels;
increasing theshare of non-fossil fuels-based electricity to 40% by2030,
enhancing its forest cover, thereby absorbing2.5 to 3 billion tonnes of carbon dioxide
India respondedto EU DisinfoLab’s discoveryof an antiPakistan disinformation campaign, saying that it is not India but acountry “next door” whichshelters terrorists and usessuch campaigns. The comment from the Official Spokesperson of the Ministry ofExternal Affairs takes on thereport of the EU DisinfoLabwhich uncovered a 15yearoperation focusing on EUand UN with fake local media and NGOs but stoppedshort of blaming the Indiangovernment directly for it.
Bhutan’s Parliament hasvoted to decriminalise samesex relations, amending anexisting law that penalisedwhat it deemed “unnaturalsex”.
Fifteenth Finance Commission chairman N.K. Singhhas called for a fresh look atthe Constitution’s SeventhSchedule, which forms thebasis for allocating subjectsto the Centre and States,and hinted at the need to fillan ‘institutional vacuum’created by the abolition ofthe Planning Commission.
The country’s foreignexchange reserves surged by$4.525 billion to touch arecord high of $579.346billion in the week endedDecember 4, the RBI’s datashowed.