Day: May 28, 2022

Weather’s Unwanted Guest: Nasty La Nina Keeps Popping up

Something weird is up with La Nina, the natural but potent weather event linked to more drought and wildfires in the western United States and more Atlantic hurricanes. It’s becoming the nation’s unwanted weather guest and meteorologists said the U.S. Western states megadrought won’t go away until La Nina does.

The current double-dip La Nina set a record for strength last month and is forecast to likely be around for a rare but not quite unprecedented third straight winter. And it’s not just this one. Scientists are noticing that in the past 25 years the world seems to be getting more La Ninas than it used to and that is just the opposite of what their best computer model simulations say should be happening with human-caused climate change.

“They (La Ninas) don’t know when to leave,” said Michelle L’Heureux, head of the National Oceanic and Atmospheric Administration forecast office for La Nina and its more famous flip side, El Nino.

An Associated Press statistical analysis of winter La Ninas show that they used to happen about 28% of the time from 1950 to 1999, but in the past 25 winters, they’ve been brewing nearly half the time. There’s a small chance that this effect could be random, but if the La Nina sticks around this winter, as forecast, that would push the trend over the statistically significant line, which is key in science, said L’Heureux. Her own analysis shows that La Nina-like conditions are occurring more often in the last 40 years. Other new studies are showing similar patterns.

What’s bothering many scientists is that their go-to climate simulation models that tend to get conditions right over the rest of the globe predict more El Ninos, not La Ninas, and that’s causing contention in the climate community about what to believe, according to Columbia University climate scientist Richard Seager and MIT hurricane scientist Kerry Emanuel.

What Seager and other scientists said is happening is that the eastern equatorial Atlantic is not warming as fast as the western equatorial Atlantic or even the rest of the world with climate change. And it’s not the amount of warming that matters but the difference between the west and east. The more the difference, the more likely a La Nina, the less the difference, the more likely an El Nino. Scientists speculate it could be related to another natural cycle, called the Pacific Decadal Oscillation, or it could be caused by human-caused climate change or both.

“At this point we just don’t know,” L’Heureux said. “Scientists are watching and I know, are actively studying. But it’s really important because of regional conditions. We need to get this right.”

La Nina is a natural and cyclical cooling of parts of the equatorial Pacific that changes weather patterns worldwide, as opposed to El Nino’s warming. Often leading to more Atlantic hurricanes, less rain and more wildfires in the West and agricultural losses in the middle of the country, studies have shown La Nina is more expensive to the United States than the El Nino. Together El Nino, La Nina and the neutral condition are called ENSO, which stands for El Nino Southern Oscillation, and they have one of the largest natural effects on climate, at times augmenting and other times dampening the big effects of human-caused climate change from the burning of coal, oil and gas, scientists said.

“They really have a very, very strong” effect, said research scientist Azhar Ehsan, who heads Columbia University’s El Nino/La Nina forecasting. “So a third consecutive La Nina is not at all a welcome thing.”

He said the dangerous heat in India and Pakistan this month and in April is connected to La Nina.

The current La Nina formed in the late summer of 2020 when the Atlantic set a record for the number of named storms. It strengthened in the winter when the U.S. western states drought worsened and in the early summer of 2021 it weakened enough that NOAA said conditions were neutral. But that pause only lasted a few months and by early fall 2021 La Nina was back, making it a double dip.

Normally second years of La Nina tend to be weaker, but in April this La Nina surprised meteorologists by setting a record for intensity in April, which is based on sea surface temperatures, Ehsan said.

“These are very impressive values for April,” L’Heureux said. Still, because La Ninas historically weaken over summer and there are slight signs that this one may be easing a bit, there’s the small but increasing chance that this La Nina could warm just enough to be considered neutral in late summer.

La Nina has its biggest effect in the winter and that’s when it is a problem for the West because it’s the rainy season that is supposed to recharge area reservoirs. But the western states are in a 22-year megadrought, about the same time period of increasing La Nina frequency.

Three factors — ENSO, climate change and randomness — are biggest when it comes to the drought, which is itself a huge trigger for massive wildfires, said UCLA climate scientist Daniel Swain. Without climate change, La Nina and bad luck could have made the drought the worst in 300 years but with climate change it’s the worst in at least 1,200 years, said UCLA climate hydrologist Park Williams.

La Nina “is a pretty important player; it may be the dominant player,” said Swain, who has a blog on western weather. “It could be responsible for one-third, maybe one-half of the given conditions if it is pronounced enough.”

“It’s much less likely that the Southwest (U.S.) will see at least even a partial recovery from the megadrought during La Nina,” Swain said.

La Nina “amps up your Atlantic storms” but decreases them in the Pacific, said Colorado State University hurricane researcher Phil Klotzbach.

It’s all about winds 10 to 12 kilometers above the water surface. One of the key factors in storm development is whether there is wind shear, which are changes in wind from high to low elevations. Wind shear can decapitate or tip over hurricanes, making them hard to strengthen and at times even stick around. Wind shear can also let dry air into hurricanes that chokes them.

When there’s an El Nino, there’s lots of Atlantic wind shear and it’s hard for hurricanes to get going. But La Nina means little wind shear in the Atlantic, making it easier for storms to intensify and do it quickly, said University of Albany hurricane researcher Kristen Corbosiero.

“That’s a really huge factor,” Corbosiero said.

“Whatever is the cause, the increasing incidence of La Ninas may be behind the increasing hurricanes,” MIT’s Emanuel said.

Some areas like eastern Australia and the arid Sahel region of Africa do better with more rain during La Nina. India and Pakistan, even though they get extra spring heat, also receive more needed rain in La Ninas, Columbia’s Ehsan said.

A 1999 economic study found that drought from La Nina cost United States agriculture between $2.2 billion to $6.5 billion, which is far more than the $1.5 billion cost of El Nino. A neutral ENSO is best for agriculture.

Columbia’s Seager said even though there may be some chance and some natural cycles behind the changes in La Nina, because there’s likely a climate change factor he thinks there will probably be more of them.

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‘Princess of the Wall of Death’: Indonesian Daredevil Defies Gravity and Stereotypes

Karmila Purba revs her motorbike under the lights of an Indonesian night carnival and rides up horizontally inside a wooden cylinder called Satan’s Barrel, drawing gasps from spectators looking down into the drum. 

With a smile on her face, Purba delights onlookers as she fearlessly pings around the bowl in Bogor, West Java, spreading her arms to collect tips waved by those above. 

The gravity-defying daredevil is among a handful of women that perform the stunt in Indonesia, zipping around a structure more commonly known as the “Wall of Death.” 

Women becoming “Wall of Death” riders is “extremely rare,” the 23-year-old told AFP before the show. 

“When I started there was no one else … so I wanted to be something different, doing something that no one else was doing.” 

For decades, the Satan’s Barrel — or “Tong Setan” — has been the main attraction at traveling funfairs in Indonesia, particularly in rural areas where there are few options for affordable entertainment. 

Using centrifugal force, riders sling their bikes around the motordrome at high speeds without protective gear as the smell of rubber fills the air. 

Purba came from humble beginnings, earning a meagre living as a street busker on the island of Sumatra in western Indonesia before switching jobs eight years ago for a better income of around 6 million rupiah ($410) a month. 

She can also earn up to 400,000 rupiah ($27) in tips on a good day. 

But at the beginning of her daredevil journey, she faced questions about her career choice. 

“People were saying to me, ‘You are a woman, why do you do something like that? It’s not for females’,” she said. 

“There was a lot of criticism.” 

Fans eventually began to praise Purba, giving her the nickname “the Princess of the Wall of Death.” 

Now she is one of the star acts of the carnival. 

“(A) female wall of death rider is very interesting and has become the main attraction in this night market because people are curious,” spectator Sumarno told AFP while watching the show.  

“They didn’t believe a woman could do something extreme like that.” 

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Insecurity Puts Mali’s Historic Djenné Mosque at Risk

Experts say Mali’s struggle against Islamist militants is putting its World Heritage sites at risk. For the first time in modern history, officials say, the annual replastering of the mud mosque in the town of Djenné in central Mali will likely be canceled because of security concerns. The concerns cast doubt onto the government’s claim it is winning the fight against terrorism.

The Great Mosque of Djenné  is the largest mud brick building in the world and was a main attraction in Mali’s formerly thriving tourism industry.

Each year the mosque is replastered in an event known as the “crépissage.” This year, the event is on the verge of cancellation for the first time, as Mali’s decadelong conflict has gradually moved south into the center of the country.

A Djenné resident who wished to remain anonymous, speaking via a messaging app from Djenné, said that in recent weeks he saw ambulances circulating in town and military helicopters flying overhead, signs of unrest in neighboring villages. The Malian army said on its Twitter account this month that four soldiers were killed in a roadside bomb attack near the town.

He said that due to insecurity, village residents have decided not to hold the crépissage this year, an event he has participated in since he was a child.

Abdramane Dembele, deputy mayor of Djenné, said that the crépissage has not yet been officially canceled, but has been delayed due to insecurity. If rescheduled, it would need to be held before the rainy season begins in June. One of the objectives of the crépissage is to protect the building from rain.

Abdoulaye Deyoko is an engineer and city planner and founder of Bamako’s School of Engineering, Architecture, and Urbanism, and a tireless advocate for Mali’s mud architecture.

Deyoko explained that the mosque is built from “banco,” a mixture of mud and small pieces of rice bran.

When it rains, he said, these small pieces have a tendency to break away. Traditionally, villagers have a celebration, a type of ritual that allows them not only to repair the mosque but to celebrate.

Deyoko said that despite this, he thinks the Djenné mosque can hold up for a year or two without the crépissage, although he said the event is important for the social life of the town, not just for technical maintenance.

The Djenné mosque and surrounding mud brick town is on the UNESCO List of World Heritage in Danger.

Ali Daou, UNESCO’s culture program director in Mali, said Djenné, like all of Mali’s four World Heritage sites, is in danger because of the ongoing hostilities. It is not just the threat of direct conflict, he said, but the difficulty of conducting the annual crépissage that puts the site at risk.

In recent months, Mali’s military government has launched a highly publicized offensive against Islamists. Many locals, though, say that these military operations target civilians rather than extremists.

The army claimed to have killed 200 terrorists in the village of Moura in March, while residents said the majority of those killed were innocent civilians.

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