Warmer seas caused by climate change are making hurricanes stronger for longer after landfall, increasing the destruction they can wreak on impact, a new study has found.
Researchers warn the finding suggests inland communities which may be less prepared than coastal regions to face hurricanes are increasingly at risk.
The effects of climate change on tropical storms including hurricanes are still being studied, although the warming planet is already known to be making storms bigger and stronger.
So academics at a Japanese university looked at data on North Atlantic hurricanes from 1967-2018 and examined their "rate of decay" how long they took to weaken in the first day after landfall.
They sought to understand what impact warming seas might have on storms when they make landfall typically when they begin to lose strength.
"We show that the decay timescale has almost doubled in the past 50 years a huge increase," Pinaki Chakraborty, a professor at the Okinawa Institute of Science and Technology Graduate University who led the study, told AFP.
That could mean destruction would "no longer be confined to coastal areas, causing higher levels of economic damage and costing more lives", he warned.
The researchers looked to see whether the longer rate of decay correlated with sea temperatures, which vary year to year, though they are rising overall.
They found a clear link: when sea surface temperature was higher, storms stayed stronger on land for longer.
But correlation does not equal causation, they said. So how to test the relationship?
They turned to computer modelling, "building" four hurricanes that developed in identical conditions except for sea surface temperature.
When each reached the equivalent strength of a Category 4 hurricane, they "switched off" the moisture supply to the model storms simulating their transition from sea to land and watched how each behaved.
- 'Growing concerns' -
"Although the intensity at landfall is the same for all four hurricanes... the intensities of the hurricanes that developed over warmer oceans decay at a slower rate," the study said.
To test the proposition further, they modelled the four hurricanes under the same conditions but this time when they made their simulated landfall, the researchers removed any stored moisture in the storm.
These "dry hurricanes" lost intensity significantly faster, and notably all at the same rate, despite having developed over seawater of differing temperatures.
Why might this be happening? The answer lies in moisture, which fuels the engine of a hurricane, the researchers said.
Storms that develop over warmer water retain more "stored moisture" akin to a small fuel tank.
This keeps them stronger for longer after landfall, even though they are cut off from the ocean supply.
There are still unanswered questions, including just how much sea temperature affects the time it takes a storm to weaken.
The landfall locations of storms have shifted over time, said Dan Chavas and Jie Chen of Purdue University's Department of Earth, Atmospheric and Planetary Sciences, in a review commissioned by the scientific journal Nature.
Terrain differences at the new landfall spots could be playing a role in hurricanes weakening more slowly, they cautioned.
Changes in the technology used to observe storms over the past decades could also affect the findings.
Despite those questions, the study "adds weight to growing concerns that tropical cyclones might become more damaging in the future," they wrote.
It should encourage researchers to "broaden their thinking" about climate change and storms, they added.
Chakraborty said he plans to expand the study to other regions affected by tropical storms to see if a similar effect is observed.
AFP RELAXNEWS
Thu Nov 12 2020
New research finds climate change is making hurricanes stronger for longer after landfall, increasing the destruction they can wreak. AFPRelaxpic
Who is Prabowo Subianto, incoming president of Indonesia?
A wealthy ex-general with ties to Indonesia's popular outgoing president and its dictatorial past, looks set to be its next leader.
Iran's supreme leader says Hamas leader's death will not halt 'Axis of Resistance'
The "Axis of Resistance", built up with years of Iranian support, includes Hamas, the Lebanese Hezbollah group, the Houthi movement in Yemen, and various Shi'ite groups in Iraq and Syria.
Putin says Russia willing to seek compromises between Iran and Israel
Russia is ready to help seek compromises between arch-foes Israel and Iran, President Vladimir Putin said on Friday, saying these would be difficult but possible.
What proposals will Russia push at the BRICS summit?
The proposal is also to establish a BRICS reinsurance company to allow uninterrupted shipment of goods and key commodities between members.
Indonesia's free meals plan in the spotlight as Prabowo readies for office
Prabowo calls the programme one of the main drivers of economic growth, eventually set to add an estimated 2.5 million jobs.
Astro AWANI's revamped English news website, AWANI International, launches on Oct 21
Astro AWANI's revamped English platform delivers in-depth global news and expert analysis to keep you informed on key developments.
Israeli strikes kill 33 people in Jabalia refugee camp in Gaza, medics say
Residents of Jabalia said Israeli tanks had reached the heart of the camp after pushing through suburbs and residential districts.
Liam Payne's ex-partner calls for media restraint after 'painful' death
Cheryl Tweedy used her statement to urge the media to remember they had a seven-year-old son, Bear, who could read the reports.
Analysts: Indonesia's strong MoF leadership team to boost investor confidence
Sri Mulyani Indrawati as head of Indonesia's Ministry of Finance is expected to instil confidence among investors.
Biden offers both a carrot and a stick to Israel as his term nears an end
Israel has frequently resisted US advice and has caused political difficulties for the Biden administration.
Putin says BRICS will generate most of global economic growth
Russian President Vladimir Putin will host a summit of the group in the city of Kazan on Oct. 22-24.
ISIS Malaysia's perspective of Budget 2025
An excellent rakyat-centric budget under the overarching principle of a caring and humane economy.
Budget 2025: Record increase in STR, SARA aid initiatives
The government will provide a significant boost to the Sumbangan Tunai Rahmah (STR) and Sumbangan Asas Rahmah (SARA) initiatives next year.
Budget 2025: EPF contributions to be made mandatory for foreign workers – PM Anwar
The government plans to make it compulsory for all non-citizen workers to contribute to the Employees Provident Fund (EPF).
What policies to expect from Indonesia's new President Prabowo
Prabowo will be open to foreign investment, his aide has said, such as by offering investors management of airports and sea ports.
Budget 2025: Govt allocates RM470 mil to empower women's participation in PMKS
The Women's Leadership Apprenticeship Program will be intensified as an effort to produce more female corporate personalities.
Israel sends more troops into north Gaza, deepens raid
Residents of Jabalia in northern Gaza said Israeli tanks had reached the heart of the camp, using heavy air and ground fire.
Indonesia ramps up security ahead of Prabowo's inauguration
Prabowo Subianto will be sworn in as Indonesia's president on Sunday with Vice President-elect, Gibran Rakabuming Raka, also taking office.
Immediate allocation of RM150 mil for local authorities, DID to tackle flash floods
Datuk Seri Anwar Ibrahim said this allocation is intended to address the recent flash floods that hit the capital and several major towns.
Budget 2025: Sabah, Sarawak to continue receiving among highest allocations - PM
Sabah and Sarawak continues to be prioritised under Budget 2025, with allocations of RM6.7 billion and RM5.9 billion respectively.