Three years of observation of atmospheric lightning phenomena — a temporary colorful lightning appearing high in the sky during thunderstorms — recently allowed a research team at National Cheng Kung University’s Department of Physics the be first in the world to present a detailed global map of the events.
In a press release yesterday, the department’s Imager of Sprite and Upper Atmosphere Lightning (ISUAL) research team said that images taken over the past three years by the satellite FORMOSAT-2 showed that 80 percent of the luminous phenomena the team recorded were “elves,” or red bursts of light in the shape of donuts in the sky caused by lightning.
The other 20 percent of the luminous events recorded by the team were made up of “sprites” — a bell-shaped flash of light appearing about 50km to 90km in the air during thunderstorms — and two other types of lightning: “halos” and “gigantic jets,” the release said.
Hsu Ruey-rong (許瑞榮), a professor of physics from the department who was responsible for the research, said that images taken by the satellite had helped the team analyze the locations where “sprites” and “elves” were more likely to be found.
The team found that “elves” usually appeared above the sea, such as the Caribbean Sea, the South China Sea, east Indian Ocean, and the central, west and southwestern Pacific Ocean, while “sprites” tended to show up above land such as central Africa, Hsu said.
Su Han-tzong (蘇漢宗), another professor of physics at the department, said the research team also found that warm seawater — above 26°C — might contribute to “elves.”
“A warm ocean surface can provide the heat source needed to drive intense oceanic lightning with very high peak currents, which usually generate elves in the ionosphere,” Alfred Chen (陳炳志), a professor of astronomy at the school, said in an interview with the New Scientist.
“Elves could have an important global effect on the lower ionosphere and the total electron content,” said Chen.
“Elf hotspots may increase the electron density of the ionosphere by 5 percent or more, which could interfere with ground and space communication as well as navigation systems,” he said.
The university organized the nation’s first “sprite” research team in 1998 and has cooperated with National Central University, National Chiao Tung University, the University of California, Berkeley, and Japan’s Tohoku University, in its research into atmospheric lightning phenomena over the past decade.
The research results of the ISUAL team — which consists of Hsu, Su, Chen and other researchers — was recently publicized in the Journal of Geophysical Research.
ADDITIONAL REPORTING BY CNA
‘DENIAL DEFENSE’: The US would increase its military presence with uncrewed ships, and submarines, while boosting defense in the Indo-Pacific, a Pete Hegseth memo said The US is reorienting its military strategy to focus primarily on deterring a potential Chinese invasion of Taiwan, a memo signed by US Secretary of Defense Pete Hegseth showed. The memo also called on Taiwan to increase its defense spending. The document, known as the “Interim National Defense Strategic Guidance,” was distributed this month and detailed the national defense plans of US President Donald Trump’s administration, an article in the Washington Post said on Saturday. It outlines how the US can prepare for a potential war with China and defend itself from threats in the “near abroad,” including Greenland and the Panama
The Chinese Nationalist Party (KMT) is maintaining close ties with Beijing, the Democratic Progressive Party (DPP) said yesterday, hours after a new round of Chinese military drills in the Taiwan Strait began. Political parties in a democracy have a responsibility to be loyal to the nation and defend its sovereignty, DPP spokesman Justin Wu (吳崢) told a news conference in Taipei. His comments came hours after Beijing announced via Chinese state media that the Chinese People’s Liberation Army’s Eastern Theater Command was holding large-scale drills simulating a multi-pronged attack on Taiwan. Contrary to the KMT’s claims that it is staunchly anti-communist, KMT Deputy
RESPONSE: The government would investigate incidents of Taiwanese entertainers in China promoting CCP propaganda online in contravention of the law, the source said Taiwanese entertainers living in China who are found to have contravened cross-strait regulations or collaborated with the Chinese Communist Party (CCP) could be subject to fines, a source said on Sunday. Several Taiwanese entertainers have posted on the social media platform Sina Weibo saying that Taiwan “must be returned” to China, and sharing news articles from Chinese state media. In response, the Mainland Affairs Council (MAC) has asked the Ministry of Culture to investigate whether the entertainers had contravened any laws, and asked for them to be questioned upon their return to Taiwan, an official familiar with the matter said. To curb repeated
Taiwan People’s Party (TPP) Chairman Huang Kuo-chang (黃國昌) yesterday appealed to the authorities to release former Taipei mayor Ko Wen-je (柯文哲) from pretrial detention amid conflicting reports about his health. The TPP at a news conference on Thursday said that Ko should be released to a hospital for treatment, adding that he has blood in his urine and had spells of pain and nausea followed by vomiting over the past three months. Hsieh Yen-yau (謝炎堯), a retired professor of internal medicine and Ko’s former teacher, said that Ko’s symptoms aligned with gallstones, kidney inflammation and potentially dangerous heart conditions. Ko, charged with
RSS