Observational study of the blue jet entering the stratosphere
Volume 589 Issue 7842, 21 January 2021Bolts of blue
The artistic reproduction of the cover depicts a blue jet seen from the International Space Station. The Blue Jet is a special "lightning bolt" that can enter the stratosphere from the top of a thunderstorm cloud upwards. These jets last less than a second, have not been adequately characterized, and the process of formation is controversial. Torsten Neubert and colleagues report observations of blue jets from a device on the International Space Station. Using the device's unobstructed observations of such events, the researchers found a jet of blue that began with a bright blue flash at the top of a thunderstorm cloud and lasted about 10 microseconds. According to the research team's analysis, this flash may be optically equivalent to a negatively narrow bipolar pulse of radio waves that initiate lightning in the cloud.
Cover image: DTU Space, Mount Visual/Daniel Schmelling
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The freshwater Arctic Ocean covered by thick ice shelves during the ice age
Volume 590 Issue 7844, 4 February 2021Salt-freeArctic seas
The cover shows Iceland's Diamond Beach and Jökulsárlón Glacier Lagoon. Researchers believe that much of the Arctic Ocean was once covered by ice shelves, but it has been difficult to obtain definitive evidence of this. Walter Geibert and colleagues' findings suggest that during the last two ice ages, the Arctic Ocean and the adjacent Nordic Sea were largely made up of fresh water and covered by a thick ice shelf. The researchers analyzed the decay of thorium-230,thorium-230 from brine in marine sedimentary cores. The authors found that thorium-230 was missing from multiple core layers in the Arctic and Nordic Seas, and suggested that meant there was no salt water. The research team believes that the ice shelf acts as a dam, separating the influx of salt water from the Atlantic Ocean. This process caused the region to be filled with fresh water 70,000-62,000 years ago and 150,000-131,000 years ago.
Cover image: Aleksandar Tomic/Alamy
Self-powered soft robot diving into the Mariana Trench
Volume 591 Issue 7848, 4 March 2021Deep-sea diver
Due to extreme conditions, the deep sea has always been an area on Earth with a large number of unknowns waiting to be explored and developed. Tiefeng Li et al. describe a soft robot capable of operating nearly 11,000 meters underwater. The robot's design was inspired by the deep-sea lionfish Pseudoliparis swirei, whose electronic components are distributed throughout the body and encapsulated as a whole in a flexible silicone material that helps it withstand the extreme pressures of the deep sea. In the test, the research team successfully made the robot work at a depth of 3224 meters below the surface of the South China Sea and 10900 meters in the Mariana Trench. An artistic representation of the cover depicts the robot and its source of inspiration, the deep-sea lionfish.
Cover image: Li Tiefeng/Zhejiang University
Climate-driven migratory bird migration routes and long-distance migration based on memory
Volume 591 Issue 7849, 11 March 2021Flight of the falcon
The cover shows a peregrine falcon wearing a GPS location tracker. Little is known about what determines the migration routes of birds in the Arctic. Xiangjiang Zhan and colleagues studied the migration routes of Falco peregrinus from their Arctic breeding grounds to different wintering grounds in Eurasia. The researchers combined satellite tracking data from 56 peregrine falcons with genomic analysis data from 35 peregrine falcons and used paleoclimate data to reconstruct the peregrine falcon's past breeding and wintering grounds distribution. They found that the migratory patterns of peregrine falcons, since the end of the last glacial period (before 22,000 years ago), have been mainly affected by environmental changes. The team also identified a genetic factor that may be beneficial to peregrine falcons— peregrine falcons that migrate longer distances carry the ADCY8 dominance allele, which the authors believe may be related to the formation of long-term memory, thereby helping peregrine falcons retain part of their migration routes.
Cover image: Andrew Dixon
Satellite imagery reveals an increase in the proportion of people exposed to flood risk
Volume 596 Issue 7870, 5 August 2021High and rising
Floods are causing more harm to people than any other environmental hazard, and the risk is rising. Beth Tellman and her colleagues combined satellite imagery and population data to develop the Global Flood Database, which reveals the extent to which flood risk is rising. The database covers 913 mega-floods from 2000 to 2018, using a total of 12,719 daily satellite images with a resolution of 250m. The research team found. Some 250 million to 290 million people were directly affected by the floods, and the proportion of people living in flood-prone areas increased by nearly a quarter between 2000 and 2015. Climate change projections suggest that this proportion will rise further through 2030, with at least 57 countries expected a greater proportion of the population to be exposed to flood risk — as shown on the cover of this year's floods in China. The research team believes. The flood database may help guide planning and adaptation policies to mitigate problems that may arise in the future.
Cover image: China Daily via Reuters
Primitive lepidosaurs from the Triassic period reveal the origins of lizard-like reptiles
Volume 597 Issue 7875, 9 September 2021Filling the gaps
The cover depicts a newly discovered lizard-like creature from the Triassic period named Taytalura alcoberi. Lepidoptera includes lepidosaurs (lizards and snakes) and beaked heads (beaked lizards), but the fossil record of lepidosaurs representing the evolutionary history of reptiles has been mutilated. Ricardo Martínez and colleagues filled the gap with Taytalura's fossilized stone bone, found in Argentina and dating back about 230 million years. This well-preserved skull belongs to a branch that evolved before the differentiation of lepidosaurs and beaked, and thus represents one of the earliest known lepidosaurs. The team pointed out that taytalura's skull has some characteristics in common with modern beaked lizards, suggesting that multiple anatomical features previously thought to exist only in beaked heads must have appeared early in the evolution of lepidosaurs.
Cover image: Jorge Blanco
Climate governance
Volume 589 Issue 7842, 21 January 2021 Bolts of blue
The cover shows a coal yard near Ordos conducting open-pit mining operations. The 26th SESSION OF THE UN Climate Change Conference, held on 31 October in Glasgow, ENGLAND, is all focused on whether the world can reach a consensus on how to make a difference in the current situation of poor response to climate change. This issue focuses on the effectiveness of the different measures and what remains to be done.
Cover image: Markus Sepperer/Anzenberger/eyevine
Domestic horses originated and expanded from the western Eurasian steppes
Volume 598 Issue 7882, 28 October 2021Horse code
The cover shows one of three horse-shaped statues of Duruthy. The statues were found in Sorde-l'Abbaye, France, and date back to the middle of the Magdalene culture, 17,000 years ago. The genetic lineage of domestic horses is not well known, and the equine ancestors of modern domestic horses are unknown. Ludovic Orlando and colleagues conducted DNA analysis on 273 ancient horses across Eurasia. Using this information, the researchers found that after about 2700 BC, there was a domestication center in the Lower Volga-Don region (now part of Russia). The team's data suggest that riding horses and using spoke chariots supported the spread of these newly domesticated horses, which for about 500 years were bred to replace all previous native horse breeds across Eurasia.
封面图片:Ludovic Orlando/Abbaye d'Arthous, Collection du Département des Landes (France)
Cardiopharyngeal structural dismantling with the fixation lifestyle of primitive saced animals
Volume 599 Issue 7885, 18 November 2021Matters of the heart
Sacs (e.g., sea squirts) are closely related to vertebrates. Most of these marine organisms can swim freely when they are young, but they will be fixed and unable to move after becoming fixed adults. However, the cysteds of the caudal sea squill do not undergo this transformation and can swim freely for life. The solid origin of the sac and this relationship to the caudal serpent has sparked much controversy. Cristian Ca estro and colleagues have proposed a new understanding of the evolution of anthocysts. The research team focused on the heart development of the tail sea sheath and found that their cardiopharyngeal gene regulatory networks were "dismantled" due to large-scale gene loss. The team believes that this dismantling caused it to lose the fixed lifestyle characteristic of the original sac. This dismantling may be related to the evolutionary adaptation of "housing", which helped the tail sea swand transition from a fixed lifestyle to its current state, a colloidal filter feeding structure unique to this type of organism, as shown on the cover.
Cover image: Alfonso Ferrández-Roldán
The mechanical forcing of mountainous terrain on the North American monsoon
Volume 599 Issue 7886, 25 November 2021Peak flow
The cover shows a bolt of lightning produced by a monsoon rainstorm as it passes through southeastern Arizona. In the summer, a belt of heavy rainfall extends along the west coast of Mexico to the southwestern United States, stretching for more than 1,000 kilometers, forming the North American monsoon. It is now widely believed that the monsoon is due to the sun's uneven heating of the ocean and land. This causes a change in air pressure, and the wind that eventually forms drags cool, moist ocean air across the land to produce rainfall. William Boos and Salvatore Pascale used research to show that the North American monsoon can be different. The monsoon here comes from winds that are turned by the mountains. Mexico's Sierra Madre Mountains cause rapids to flow, which lift warm, moist air and create convective rainfall. The researchers note that although ground heating does exist, its effects are not enough to explain the North American monsoon, meaning that the North American monsoon should have formed under mechanical forcing.
Cover image: John Sirlin/Alamy
A strange tail weapon of a transitional species of ankylosaur in the sub-Antarctic region of Chile
Volume 600 Issue 7888, 9 December 2021Armed response
We learn that ankylosaurs had tail weapons, including spines from the stegosaurus genus and tail hammers from the genus Ankylosaurus. A new species of ankylosaur reported by Alexander Vargas and colleagues possessed a strange tail weapon similar to the Aztec Warhammer. This ankylosaurus dinosaur, named Stegouros elengassen, has a near-intact skeleton found in southern Chile and lived about 75 million years ago. Its massive tail weapon is made up of 7 pairs of flat ossified compounds fused to form a fern-like structure. The researchers identified Stegouros as related to The Ankylosaurus of the genus Kunbarrasaurus found in Australia and the Genus Antarctopelta found in Antarctica. The authors argue that when the continents of Lauya and Gondwana were finally separated in the Late Jurassic, different branches of the ankylosaur lineage may have lived on these two supercontinents.
Nature's 10 2021
Volume 600 Issue 7890, 23 December 2021One year. Ten stories
The last issue of 2021 magazine looks back at the past 12 months through the top ten scientific figures who participated in witnessing the scientific development of the year. The cover shows the intrinsic connection between the different life forms on Earth — from the ocean to the land to the air, from microbes to the largest mammals. The fragility of the planet is a very prominent theme this year, and the international community has launched a global consultation aimed at protecting biodiversity and preventing the worst consequences of climate change.
In the field of earth sciences, there are Victoria Tauli-Corpuz, who advocates for the rights of indigenous peoples in forests and biodiversity, Zhang Rongqiao, chief designer of China's first Mars exploration mission "Tianwen-1", and Friederike Otto, who devotes himself to the study of extreme weather events.
Cover image: Elena Galofaro Bansh
Editor: Wan Peng
Editor: Xu Hongxi
Proofreader: Wang Haibo