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Indian Ocean temps vary from side to side

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New research on the Indian Ocean dipole shows how melting ice water from massive glaciers can ultimately lead to droughts and flooding in East Africa and Indonesia.With a new analysis of long-term climate data, researchers say they now have a much better understanding of how climate change can cause sea water temperatures on one side of the Indian Ocean to be so much warmer or cooler than the temperatures on the other—a phenomenon that can lead to sometimes deadly weather-related events like megadroughts in East Africa and severe flooding in Indonesia.

The analysis, described in a new study in Science Advances, compares 10,000 years of past climate conditions reconstructed from different sets of geological records to simulations from an advanced climate model.

The findings show that about 18,000 to 15,000 years ago, as a result of melted freshwater from the massive glacier that once covered much of North America pouring into the North Atlantic, ocean currents that kept the Atlantic Ocean warm weakened, setting off a chain of events in response. The weakening of the system ultimately led to the strengthening of an atmospheric loop in the Indian Ocean that keeps warmer water on one side and cooler water on the other.

This extreme weather pattern, known as a dipole, prompts one side (either east or west) to have higher-than-average rainfall and the other to have widespread drought. The researchers saw examples of this pattern in both the historical data they studied and the model’s simulation. They say the findings can help scientists not only better understand the mechanisms behind the east-west dipole in the Indian Ocean, but also one day help to produce more effective forecasts of drought and flood in the region.

“We know that in the present-day gradients in the temperature of the Indian Ocean are important to rainfall and drought patterns, especially in East Africa, but it’s been challenging to show that those gradients change on long time-scales and to link them to long-term rainfall and drought patterns on both sides of the Indian Ocean,” says James Russell, a study author and professor of earth, environmental, and planetary sciences at Brown. “We now have a mechanistic basis to understand why some of the longer-term changes in rainfall patterns in the two regions have changed through time.”

In the paper, the researchers explain the mechanisms behind how the Indian Ocean dipole they studied formed and the weather-related events it led to during the period they looked at, which covered the end of the last Ice Age and the start of the current geological epoch.

The researchers characterize the dipole as an east-west dipole where the water on the western side—which borders modern day East African countries like Kenya, Ethiopia, and Somalia—is cooler than the water on eastern side toward Indonesia. They saw that the warmer water conditions of the dipole brought greater rainfall to Indonesia, while the cooler water brought much drier weather to East Africa.

That fits into what is often seen in recent Indian Ocean dipole events. In October, for example, heavy rain led to floods and landslides in Indonesian islands of Java and Sulawesi, leaving four people dead and affecting over 30,000 people. On the opposite end, Ethiopia, Kenya, and Somalia experienced intense droughts starting in 2020 that threatened to cause famine.

The changes the authors observed 17,000 years ago were even more extreme, including the complete drying of Lake Victoria—one of the largest lakes on Earth.

“Essentially, the dipole intensifies dry conditions and wet conditions that could result in extreme events like multi-year or decades-long dry events in East Africa and flooding events in South Indonesia,” says Xiaojing Du, a postdoctoral researcher in the Institute at Brown for Environment and Society and Brown’s department of earth, environmental and planetary sciences, and the study’s lead author. “These are events that impact people’s lives and also agriculture in those regions. Understanding the dipole can help us better predict and better prepare for future climate change.”

The dipole the researchers studied formed from the interactions between the heat transport system of the Atlantic Ocean and an atmospheric loop, called a Walker Circulation, in the tropical Indian Ocean. The lower part of the atmospheric loop flows east to west across much of the region at low altitudes near the ocean surface, and the upper part flows west to east at higher altitudes. The higher air and lower air connect in one big loop.

Interruption and weakening of the Atlantic Ocean heat transport, which works like a conveyor belt made of ocean and wind currents, was brought on by massive melting of the Laurentide ice sheet that once covered most of Canada and the northern US. The melting cooled the Atlantic and consequent wind anomalies triggered the atmospheric loop over the tropical Indian Ocean to become more active and extreme. That then led to increased precipitation in the east side of the Indian Ocean (where Indonesia sits) and reduced precipitation in the west side, where East Africa sits.

The researchers also show that during the period they studied, this effect was amplified by a lower sea level and the exposure of nearby continental shelves.

The scientists say more research is needed to figure out exactly what effect the exposed continental shelf and lower sea level has on the Indian Ocean’s east-west dipole, but they’re already planning to expand the work to investigate the question. While this line of the work on lower sea levels won’t play into modeling future conditions, the work they’ve done investigating how the melting of ancient glaciers impacts the Indian Ocean dipole and the heat transport system of the Atlantic Ocean may provide key insights into future changes as climate change brings about more melting.

“Greenland is currently melting so fast that it’s discharging a lot of freshwater into the North Atlantic Ocean in ways that are impacting the ocean circulation,” Russell says. “The work done here has provided a new understanding of how changes in the Atlantic Ocean circulation can impact Indian Ocean climate and through that rainfall in Africa and Indonesia.”

The study had funding from the Institute at Brown for Environment and Society and the National Science Foundation.



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Diesel replacement costs up to Rs. 4.5 bn in April

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Norochcholai Power Plant

Coal power generation falls by 27 GWh

A sharp decline in coal-fired electricity generation in April 2026, compared to the corresponding month last year, may have cost Sri Lanka more than Rs. 4.5 billion, as the country was compelled to rely on significantly more expensive diesel-powered generation to make up the shortfall, according to power sector data.

The coal-based electricity generation, in April 2026, was 27 GWh lower than in April 2025, a development that has sparked concern among energy experts and economists over the mounting financial burden on the country’s already strained power sector.

Industry calculations reveal that generating the lost 27 GWh through diesel-fired power plants would require approximately 8.1 million litres of fuel, based on a standard consumption rate of 0.3 litres per kilowatt-hour.

With fuel costs estimated at around USD 286 per barrel, or roughly USD 1.80 per litre, the replacement power would have cost approximately USD 14.57 million. At the prevailing exchange rate of about Rs. 315 to the US dollar, the bill exceeds Rs. 4.5 billion for April alone.

Energy sector analysts say the figure highlights the enormous economic value of maintaining high availability at coal-fired power plants, particularly at a time when Sri Lanka is seeking to reduce electricity costs and strengthen energy security.

“The financial impact of losing low-cost coal generation is substantial. Every unit not generated by coal has to be replaced by a much more expensive source, usually diesel or fuel oil, which ultimately affects the finances of the power sector and the wider economy,” a senior energy analyst said.

Even under a more conservative calculation, based on the average electricity generation cost of around Rs. 72 per unit recorded in 2025, the loss remains significant. The 27 million units not generated from coal would translate into an additional cost burden of nearly Rs. 2 billion.

The decline in coal generation comes at a critical juncture for Sri Lanka’s energy sector.

 The government has repeatedly emphasised the need to maintain affordable electricity tariffs, while reducing dependence on imported fossil fuels and expanding renewable energy capacity.

Experts warn that any sustained reduction in low-cost baseload generation could undermine these objectives, increasing the need for costly thermal power and placing additional pressure on foreign exchange reserves.

The latest figures are expected to intensify scrutiny of generation planning, fuel procurement strategies and the operational performance of major power plants. They also underscore the importance of ensuring uninterrupted operation of coal-fired facilities until sufficient renewable and storage capacity is available to replace them reliably.

With the country striving to maintain economic stability and energy affordability, analysts argue that avoiding such generation shortfalls must remain a top priority for policymakers and power sector planners.

By Ifham Nizam

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Sallay on hunger strike: Counsel warns CID

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Sallay

Asith Siriwardena Counsel for former Director of State Intelligence Service, Major General (Retd.) Suresh Sallay, detained under the Prevention of Terrorism Act (PTA) over the 2019 Easter Sunday attacks, has called upion the Director of the CID, SSP G. S. Abeysekara, to transfer his client either to a private or government hospital to receive urgently needed teatment.

Sallay was on a hunger strike, claiming mistreatment by the CID, his wife said, after visting him, yesterday.

Siriwardena wrote to the CID Director yesterday (07) after Sallay was visited by his wife, son and brother.

The text of the letter: “The family observed that Mr. Sallay’s physical condition has deteriorated to an alarming and critical level.

“He is reportedly unable to attend the visitation without the physical assistance of two officers. During the visit, he informed his family that he had refused medication, saline, food, and water. He further expressed a belief that his death is imminent and requested that arrangements be made for the donation of his eyes. He also requested an immediate visit from his Attorney for the purpose of executing his last will and other related legal documentation.

“These statements, and circumstances, demonstrate a grave deterioration in his physical and psychological condition. It is apparent that he is no longer capable of making rational decisions concerning his own welfare, health, and survival.

The prolonged conditions, under which he is presently being held have, at the very least, created a serious and immediate risk to his life.

“The State assumes a non-delegable duty of care toward every person held in its custody. Once an individual is deprived of liberty, the responsibility for safeguarding that person’s life, health, and wellbeing rests squarely upon the authorities exercising control over that individual. Any failure to discharge that duty in the face of a known and imminent medical emergency is a matter of the utmost legal seriousness.

“You are hereby formally notified that Mr. Sallay requires immediate medical intervention by qualified independent medical professionals and urgent transfer to an appropriate hospital facility capable of providing comprehensive assessment and treatment. Any delay, refusal, or failure to act despite clear knowledge of his precarious condition may give rise to personal and institutional liability under the criminal and civil law of Sri Lanka

“Should General Sallay suffer irreversible injury or death while remaining in the present conditions despite this explicit warning, it will be open to the relevant authorities, courts, and investigative bodies to examine whether such conduct amounts to a deliberate disregard of a known and foreseeable risk to life. Those responsible for decisions concerning his continued detention and medical care may be required to account personally for their actions and omissions.

“Accordingly, I demand that:

1. Mr. Sallay be transferred forthwith to a government or private hospital equipped to provide urgent medical treatment;

2. He be examined immediately by independent medical specialists, including psychiatric professionals if necessary; His legal representatives and family be granted reasonable access to him;

3. A written update on his medical status and the measures taken for his protection be provided without delay. This letter constitutes formal notice. Any further failure to act despite knowledge of the circumstances set out herein will be relied upon in any future judicial, criminal, constitutional, or international proceedings arising from harm suffered by my client.”

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Opp. questions why Rs 10 bn meant for Ditwah victims held in Treasury account

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Sanjeewa

The Opposition says the NPP government should explain why the funds received by Rebuilding Sri Lanka haven’t been utilised to provide relief to those affected by Ditwah cyclone in late November last year.

The failure on the part of the government to utilise as much as Rs 10 bn, received from local and foreign donors, came to light when the National Audit Office (NAO) appeared before the Public Finance Commission recently.

The NAO told the House Committee that no statutory fund currently existed under the name “Rebuilding Sri Lanka” and the programme operated through an account maintained under the Deputy Secretary to the Treasury.

The NAO declared that no payments had been made through this account to date.

Former SLPP MP Sanjeewa Edirimanne said that until the disclosure made by the NAO the country had been led to believe the Rebuilding Sri Lanka fund provided post-Ditwah relief. Pointing out that JVP General Secretary Tilvin Silva’s declaration in Jaffna that funds allocated to hold Provincial Council polls

had been utilised to assist Ditwah victims, Edirimanne said such blatant lies were propagated while the government held on to Rs 10 bn meant for the disaster victims.SJB MP Mujibur Rahman questioned the rationale behind keeping funds received specifically for Ditwah victims still living under extremely difficult conditions. (SF)

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