Union Minister G. Kishan Reddy to move the motion to elect, in the manner as directed by the Chairman, one member for the Central Advisory Board of Archaeology…reports Asian Lite News
Amid continuous disruption since the first day of the ongoing Monsoon Session, the Centre will on Thursday move ‘The Indian Antarctic Bill, 2022’ for consideration and passing in the Rajya Sabha.
Union Minister Dr Jitendra Singh will move the bill.
He will also make a statement regarding the status of implementation of recommendations/observations contained in the report of the department-related Parliamentary Standing Committee on Science and Technology, Environment, Forests and Climate Change on Demands for Grants (2022-23) pertaining to the Department of Science and Technology.
Meanwhile, Union Minister G. Kishan Reddy to move the motion to elect, in the manner as directed by the Chairman, one member for the Central Advisory Board of Archaeology.
Union Minister Arjun Ram Meghwal will make a statement regarding the status of implementation of recommendations/observations contained in the report of the Department-related Parliamentary Standing Committee on Transport, Tourism and Culture on Demands for Grants (2022-23).
Minister Ajay Bhatt will make statement regarding the status of implementation of recommendations/observations contained in the Department-related Parliamentary Standing Committee on Transport, Tourism and Culture on the ‘Development of Tourism in Jammu and Kashmir’.
Opposition parties are however, likely to continue their protest demanding the revocation of suspension of their members and discussion on price rise and other issues.
Twenty opposition members have been suspended for disrupting the House proceedings and utter disregard to the Chair.
South-easterlies become southwest (summer) monsoon winds after crossing the equator, therefore, a strong correlation between them is expected…writes Nivedita Khandekar
Identifying several occurrences of interchanging intense and weak monsoon circulation events during the 145 kyr period (roughly a millennia), Indian scientists have found that warm/cold conditions in Antarctica show a near one-to-one coupling with weak/strong monsoon phases, suggesting a strong mechanistic link between them during the period.
Four scientists from National Centre for Polar and Ocean Research (NCPOR), Goa, under the Ministry of Earth Sciences, and the School of Earth, Ocean and Atmospheric Sciences, Goa University, reconstructed the dynamics of the summer monsoon circulation from an upstream region, which is ideally suited for exploring its link with the southern high-latitude climate. The available records of past summer monsoon variability are predominantly based on reconstruction of downstream hydrology, which is identifiable with the thermodynamics of the system.
Antarctica
“The influence of northern high latitude climate variability on the South Asian Summer Monsoon has been extensively studied using both instrumental and proxy based climate data. In comparison, only a few studies have attempted to explore the southern high latitude association of the South Asian Summer Monsoon,” the study said.
South Asian summer monsoon transports large amount of heat and moisture across the equator. A low-pressure system develops over the northwest Indian subcontinent and the Tibetan plateau as a result of sensible heating due to the seasonal position of the Sun. South-easterlies become southwest (summer) monsoon winds after crossing the equator, therefore, a strong correlation between them is expected.
These scientists Manish Tiwari, Sidhesh Nagoji and Rahul Mohan from NCPOR, Goa and Vikash Kumar from Goa University, compared the 145 kyr long record of summer monsoon variability inferred through south-easterlies strength with that of earlier published 2003-reconstruction from the western Arabian Sea reflecting the southwest monsoon wind strength.
They presented 145 kyr long new data – oxygen and carbon isotopic abundance of two depth-stratified species of foraminifera viz. Globigerinoides ruber and Globorotalia menardii – from a sediment core on sub-millennial to millennial scale resolution from the southwestern tropical Indian Ocean, a region swept by the southeasterly wind during boreal summer, which transforms to the southwest monsoon wind after crossing the equator.
The findings from the study – published as ‘a 145 kyr record of upstream changes in Indian monsoon circulation and its link to southern high-latitude climate’ in journal ‘Polar Science’ in October – said “are consistent with our results where warm (cold) Antarctic conditions appear to cause synchronous decline (increase) in monsoon circulation, most likely through an equatorial Indian Ocean bridge”.
The tropical Indian Ocean, apart from being directly affected by the summer monsoon winds, is also ideally suited for exploring any high southern-latitude inter-hemispheric influence on the circulation. “Here, we report oxygen and carbon isotopic abundance of two depth-stratified foraminifera species from a sediment core from the southwestern tropical Indian Ocean covering significant parts of the last two glacial periods,” the study said, adding: “Past upwelling record constructed using the oxygen isotopic composition of depth-stratified species of foraminifera indicates periods of high and low summer monsoon activity from 187.5 kyr to 41.4 kyr BP”.
Antarctica
The carbon isotopic composition primarily records signatures of monsoon induced upwelling during this period. Spectral and wavelet analysis shows dominant power in the precession band throughout the 145 kyr period. “Our record of summer monsoon variability matches with a multi-proxy record of monsoon wind stress from the Western Arabian Sea, a region dominated by high seasonal south-westerly summer monsoon wind. Comparison of our record with the Antarctic climate record during the last two glacial periods suggests coherent changes in cross-equatorial summer monsoon flow and Antarctic temperatures where warm (cold) conditions in Antarctica were phase linked to weak (strong) monsoon circulation.”
It appears that millennial scale variability in the southern high latitude region significantly modulates sub-orbital variance of cross-equatorial monsoon flow, most likely by influencing the sea surface temperatures (SST) in the tropical Indian Ocean, the scientists said.
Indian scientists to dig deep ice to know past climate at Antarctica
It is for the first time that Indian scientists would drill up to 500 metres and pull put ice cores that are repositories of information of the past climate events for long years duration, reports Nivedita Khandekar
Indian scientists from the 41st expedition to Antarctica have embarked upon a multi-year study of the movement of deep ice sheets near the coast to understand the past climate, which in turn, will help understand how it will change in decades to come.
It is for the first time that Indian scientists would drill up to 500 metres and pull put ice cores (cylindrical ice bars) that are repositories of information of the past climate events for long years duration.
Antarctica
“This helps us study the past climate of up to 10,000 years through ice cores that have trapped CO2 from the atmosphere from past.
Called SIWHA or ‘Sea Ice and Westerly winds during the Holocene in coastal Antarctica,’ it is a joint Indo-UK-Norway study with India’s National Centre for Polar and Ocean Research (NCPOR), British Antarctic Survey (BAS) and Norwegian Polar Institute (NPI) as collaborators.
“The 41st expedition is already at Antarctica. A team is carrying out geo-physical survey to assess correct places to drill. By next year, they will be ready with data that can tell us where exactly to drill. Drilling will start in 2022-23 season,” said NCPOR, Director, Group Director (Polar Science), Dr Thamban Meloth.
“The drilling will be done nearer to the coast with a specific reason to understand how the southern ocean which takes so much of carbon dioxide, which changed in the past. It would have a meaning for us to understand how it will change in the coming decades,” Meloth added.
Collecting the ice cores from near the coast is important and much more challenging as it is much more warmer around Antarctica. “So we need to take it from the right place actually to activate it to understand the properties below the ice.”
A specialised equipment, ground penetrating radar, helps the team identify the ice layering and the bedrock, during the geophysical survey.
The NCPOR has been carrying out studies related to ice cores for few years now but it was limited to 100-150 metres. It is only now that digging will be done for the first time till 500 metres. The fragile ice cores are carefully stored and brought back to NCPOR maintaining minus 20 degrees temperature. To whichever depth digging is done, the cores are collected at every metre. (E.g. a dig of 150 metres will result in 150 ice cores).
For analysis of the cores, the cores are cut into half horizontally. One half is sent into archive. Ice cores are also cut into 5 cm thick slices, each of which reveals climate features from that particular time/age.
In general, the world’s oceans absorb 90 per cent of more heat that is released from burning fossil fuels and much of carbon dioxide. And of that, the southern ocean that surrounds Antarctica can be termed as primary storage house for both heat and CO2. So anything that changes on Antarctica can have an impact on global climate.
Hence, collecting the cores from near the coast is needed. But getting the cores is much more challenging as it is much more warmer around Antarctica. So we need to take it from the right place actually to activate it. So that we also understand the properties below the ice.
A specialised equipment called the ground penetrating radar which will tell us the ice layering and the bedrock, how they are placed. All that information we will get through the geophysical survey.
One simulation indicated that by the end of this century global sea-level rise caused by the melting of the West Antarctic Ice Sheet would increase 20 percent by the water expulsion mechanism…reports Asian Lite News.
The global sea-level rise caused by the melting of the West Antarctic Ice Sheet is likely to increase by 20 percent by the end of this century, researchers have warned.
The global sea level rise linked to melting of the West Antarctic Ice Sheet has been significantly underestimated in previous studies, meaning sea level in a warming world will be greater than anticipated, said researchers from Harvard University in the US.
The study, published in the journal Science Advances, made new calculations, referred to as a water expulsion mechanism.
This occurs when the solid bedrock the West Antarctic Ice Sheet sits on rebounds upward as the ice melts and the total weight of the ice sheet decreases. The bedrock sits below sea level so when it lifts, it pushes water from the surrounding area into the ocean, adding to global sea level rise.
One simulation indicated that by the end of this century global sea level rise caused by melting of the West Antarctic Ice Sheet would increase 20 per cent by the water expulsion mechanism.
The new predictions showed that in the case of a total collapse of the ice sheet, global sea level rise estimates would be amplified by an additional metre within 1,000 years.
“The magnitude of the effect shocked us. Previous studies that had considered the mechanism dismissed it as inconsequential,” said Linda Pan, from the varsity.
“If the West Antarctic Ice Sheet collapsed, the most widely cited estimate of the resulting global mean sea level rise that would result is 3.2 metres,” added Evelyn Powell, graduate student at the varsity.
“What we’ve shown is that the water expulsion mechanism will add an additional metre, or 30 per cent, to the total,” said Powell.
The researchers noted their calculations show that, in order to accurately estimate global sea level rise associated with melting ice sheets, scientists need to incorporate both the water expulsion effect and the mantle’s low viscosity beneath Antarctica.
“Sea level rise doesn’t stop when the ice stops melting,” Pan said. “The damage we are doing to our coastlines will continue for centuries.”
