{"id":19938,"date":"2022-03-30T14:52:29","date_gmt":"2022-03-30T13:52:29","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=19938"},"modified":"2022-03-30T14:52:29","modified_gmt":"2022-03-30T13:52:29","slug":"earths-atmosphere-temperature-changes-and-climate-shifts","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/earths-atmosphere-temperature-changes-and-climate-shifts\/19938\/","title":{"rendered":"Earth’s atmosphere revealed by temperature changes and climate shifts"},"content":{"rendered":"
Scientists have discovered argon trapped in air-hydrate crystals in ice cores, which can be utilised to reconstruct past temperature changes and climate shifts.<\/p>\n
On the gigantic sheets of ice that stretch across Greenland and Antarctica, the temperature is so low that not even the summer Sun can melt the snow deposited onto them. As the snow accumulates without melting and settles deeper into the ice sheet, it traps air from the atmosphere, which forms small air bubbles when the snow transforms into ice.<\/p>\n
Over centuries or millennia, the ice builds up, increasing the pressure and dropping the temperature in the bubbles, until the trapped atmospheric molecules convert into cage-like crystals, preserving the ancient air samples for hundreds of thousands of years. These crystals, called \u2018air-hydrate crystals,\u2019 could reveal exactly how the Earth\u2019s atmosphere<\/a>, and climate, has shifted over hundreds of thousands of years\u2014 so long as their composition is accurately measured.<\/p>\n Previous measurement methods were limited to a couple of elements, such as oxygen and nitrogen. Now, this research team has developed a new approach to identify more elusive, previously unconfirmed constituents, such as argon, which could help reconstruct a more precise understanding of past climates.<\/p>\n These findings were published in the\u00a0Journal of Glaciology<\/em>.<\/p>\n \u201cThe air bubbles in an ice core are the only known paleoenvironmental archive of the actual ancient atmosphere with a time axis in the depth direction,\u201d explained Tsutomu Uchida, lead author and an Associate Professor in the Faculty of Engineering at Hokkaido University.<\/p>\n He explained that argon could be extracted from the ice via melting or cutting, but its location in the undisturbed ice was a mystery. \u201cIf we can understand where argon is located in ice, we can improve our understanding of the movement of gas molecules in ice and contribute to improving the accuracy of environmental reconstruction.\u201d<\/p>\n The researchers examined five air-hydrate crystals in an ice core extracted from Greenland and containing ice dating to about 130,000 years ago. They utilised a combination of scanning electron microscopy and energy-dispersive X-ray spectroscopy to visualise and identify the molecules contained in the air-hydrate crystals\u2014this revealed the presence of argon.<\/p>\nHow is this new method improved?<\/h3>\n