Warming May Make Hurricanes Weaken More Slowly After Landfall

first_imgA hurricane is essentially a heat engine, a rotating storm fueled by moisture from the warm ocean. The prevailing theory as to how hurricanes weaken after landfall is that once they lose that source of fuel, friction with land causes their spinning to slow down.Dr. Chakraborty likened it to a swirling cup of tea. “Over the ocean, because the moisture supply is there for the heat engine, you’re constantly stirring the tea,” he said. But when it hits land the supply is cut off, the stirring stops and friction causes the swirling to slow“Importantly, thermodynamics plays no role” in this process of slowing, according to the theory, he said.What he and his co-author suggest, however, is that the moisture remaining in the storm plays a thermodynamic role, affecting the rate at which the storm weakens. And in a warming climate, with warmer sea-surface temperatures, there is more moisture remaining in the storm.“Once we understand that moisture plays a key role, the connection with climate becomes evident,” Dr. Chakraborty said.Their hurricane simulations allowed them to test the idea that moisture plays a role by creating “dry” hurricanes, without moisture, that decayed much more rapidly than normal ones. The models also allowed them to determine that factors like topography and the weather inland played less of a role in storms’ weakening.Dr. Camargo said one potential weakness of the study was that the models used were, by necessity, rather simple. Modeling hurricanes after landfall is difficult, she said. “It’s a hard problem. The models have to capture a lot of things that are going on — the interaction with topography, for instance.”“I don’t know if what they did in the model is the best way to represent landfalling hurricanes,” Dr. Camargo added. “But at least in this model, it seems to agree with their idea.”Dr. Chakraborty said he was not surprised there was some skepticism about the findings. “Overall, our study challenges widely-held ideas about hurricane decay,” he said. “I hope this will spur more research and shed new light on this important area that is long thought to be well understood.” In studying the effects of climate change on hurricanes, scientists have focused on what occurs over water, when storms are forming and strengthening, picking up heat and moisture as they churn over the ocean.But a new study looks at what happens after hurricanes make landfall and work their way inland. The research suggests that climate change is affecting storms during this phase of their life as well, causing them to weaken more slowly and remain destructive for longer.- Advertisement – The findings could have implications for how emergency-management agencies prepare for storms post-landfall.In the study, published Wednesday in the journal Nature, Lin Li and Pinaki Chakraborty of the Okinawa Institute of Science and Technology Graduate University in Japan analyzed data from North Atlantic hurricanes that made landfall from 1967 to 2018, looking at the decay in intensity, or wind speed, of the storms in the first day after hitting land. One prominent hurricane researcher, Kerry Emanuel of the Massachusetts Institute of Technology, said he was skeptical of the findings. In an email message, Dr. Emanuel said he disagreed with the researchers’ theoretical argument and that the data and simulations, “while suggestive, do not definitively prove the case that decay is slower in warmer climates independent of other factors, such as storm size.” – Advertisement – But other researchers said the study was compelling and opened up a new field of hurricane research, on their behavior over land. Even weakened, winds from these storms can topple trees and power lines, damage homes and cause other destruction well inland. Dan Chavas, an atmospheric scientist at Purdue University who wrote an article accompanying the paper in Nature, said the work was “definitive in identifying a topic almost no one has thought about and could be very important.”Suzana Camargo, a hurricane researcher at the Lamont-Doherty Earth Observatory, a part of Columbia University, said that she and colleagues published a study last year that showed that stronger hurricanes produced more precipitation after making landfall.In the new study, she said, “they are saying that moisture stays in the storm for a while, and that completely makes sense with what we saw in our study.” They found that while 50 years ago a typical storm would have lost more than three-quarters of its intensity in the first 24 hours, when it might travel several hundred miles inland, now it would only lose about half.- Advertisement – – Advertisement – “The decay has slowed down tremendously over the last 50 years,” Dr. Chakraborty said in an interview. “There may very well be a climatic link.”Comparing the data on decay with changes in sea-surface temperatures, and then using simulations of hurricanes moving onto land, the scientists discovered what they say is the link: Rising ocean temperatures linked to global warming are causing the storms to weaken more slowly, even after storms move away from the source of the moisture.The scientists cautioned that there were caveats to their research, among them that they used a relatively small data set — only 71 hurricanes made landfall over five decades.last_img read more

Cricket News Marnus Labuschagne – A case to be studied

first_imgNew Delhi : Let’s write about Marnus Labuschagne today. Let’s write about him tomorrow. Let’s not forget to write about him a day after. Marnus Labuschagne has set some standards in his initial days of International cricket after the innings he played under pressure in second Ashes Test against England.Imagine a Test match going and as the manager’s hands the team sheet – your name isn’t there. This means, you have been asked to start on the bench and serve water as and when required by on-field players. Now, while you’re in non-match mood, you get to know that you need to play as Steve Smith, who smashed two centuries and 92 in three innings was hit by a bouncer by Jofra Archer.Becoming the first-ever batsman to be concussion replacement, Labuschagne smashed a gritty 59 as Australia survived to claim a draw and preserve their 1-0 series lead.If that wasn’t enough, on Tuesday morning – not more than an hour after Smith was ruled out of this week’s third Test – Labuschagne was hit square in the grille by a Mitchell Starc snorter while batting in the nets, requiring medical attention for the second time in the space of four days.Just as he did at Lord’s, Labuschagne waved the medics away, insisting he was fine.Needing 288 to avoid an innings defeat by Lancashire, the Welsh county were skittled for 138, losing inside three days. But the fact that they remain third in the Division Two table owes much to their 25-year-old Australian overseas player with the unpronounceable name who smashed a century on his championship debut against Northants and went on to plunder four more before receiving an Ashes call-up from Australia’s selectors.Labuschagne’s 1,114 runs this summer makes him the competition’s leading run-scorer by a distance, and a major reason why a team who finished bottom of Division Two last season are now challenging for promotion to Division One.Labuschagne – The replacement Australia wantedBorn in Klerksdorp, in South Africa’s North West province, Australia’s man of the moment grew up speaking Afrikaans, apparently only becoming proficient in English after his family emigrated to Brisbane when he was 10. It seems he was always fluent with bat and ball, though.A cricket-mad teenager Labuschagne was operating the Hot Spot cameras at the Gabba when Peter Siddle recorded an Ashes hat-trick in the first Test in 2010. He played for Queensland at under-12, under-15, under-17, and under-19 level, and for Redlands Tigers in grade cricket.It was actually through the Redlands connection that Glamorgan signed him.Labuschagne had already made his Test debut by then, of course, so he wasn’t a complete unknown. Called up for Australia’s series against Pakistan in the UAE last year, he made a duck in Dubai before scoring 25 and 43 in the second Test in Abu Dhabi. It was his fielding and leg-spin which drew greater attention, Labuschagne taking 3-45 with the ball and producing one particularly smart catch at short leg to dismiss Mohammad Hafeez.It was not enough to secure him a central contract with Cricket Australia, though, opening the door to Glamorgan. Their gamble paid off in spades.Australia will hope Labuschagne’s bountiful summer does not end now. He has produced to be an exceptional player who has adapted to the conditions well and taken pressure off the experienced campaigners at this age. Being the first choice for that middle-order spot in the next Test, Labuschagne will look to grab the opportunity with both hands. And if he can replicate last game heroics again, he may well prove to be the difference between two sides.What will Labuschagne become or not, who knows till then, stay with those timely inside out cover drives and pulls in front of square. Sometimes, a cricketer is just about his cricket. And there’s no nickname needed. For all the Latest Sports News News, Cricket News News, Download News Nation Android and iOS Mobile Apps.last_img read more