字幕列表 影片播放 列印英文字幕 What's that in the sky? Is that a bird? Superman? Chemtrails? Cloud seeding? What the hell is cloud seeding? Hey guys, Julia here for DNews Humans like to make it rain. From rain dances to Storm in X-men we've always dreamed of controlling the weather. Apart from rituals and science fiction, science might have found a way. Clouds are made of millions of tiny water droplets. But these droplets hang out in the air unless they stick to tiny particles. Then they become heavy enough to fall. Normally these particles are things like dust. A study published in the journal Geophysical Research Letters found that pollen might help form clouds too. Previously scientists thought that pollen grains were too large to have any effect on weather. Yet this new research suggests that when pollen gets wet it breaks apart into smaller pieces. And these smaller pieces could make the building blocks of clouds. So it seems like a small leap of logic to find a way we could help the process along. Maybe we could make clouds out of thin air. Sound like science fiction? Well it's already a thing. It's been a thing in the American west for decades already. In California, water agencies and utilities dish out $3-to-5 million bucks a year on it. Cloud seeding produces nucleation, when water particles attach to other small particles and condenses. Basically it makes water vapor form clump into a cloud. If it gets heavy enough, it falls to the ground as rain. One study published in the Journal of Applied Meteorology and Climatology found that this process can improve rainfall by up to 15%. While that doesn't seem like a lot, this technique proved effective in a desert in 2010. An 11 million dollar project produced 52 rain storms in the Abu Dhabi desert. In this case, scientists working for the United Arab government designed ionizers, which produced charged particles. As they rose into the atmosphere, these particles collected dust. When water particles condensed around the dust, it formed clouds… which turned into rain. Worried your wedding day might be a little wet? Well, London based luxury travel company, Oliver's Travels can help. they'll have a pilot fly near your event location and sprinkle a few silver iodide particles into the air a few days before the shindig. These particles, look very close to ice on a molecular level. So they make water condense and well you get the idea. Rain happens. This clears the air, so clouds won't build up on your big day. Although prepare to cough up a pretty penny. The service can run $150,000. I know what you're thinking - can we just make a bunch of rainclouds and end the drought? Well there are some skeptics, one study published in the journal Atmospheric Research found some cloud seeding attempts aren't all that successful. Looking over a 50 year period, the researchers conclude that an increase in rainfall was the result of chance, not cloud seeding. But other scientists think it could tame hurricanes. In a study published in the journal Atmospheric Science Letters researchers create climate models to understand how creating clouds could cool down the oceans. Hurricanes get whipped by warm waters in the ocean. As sea surface temperatures heat up, hurricanes get more energy. By creating clouds above ocean hot spots, the clouds could act like reflectors, bouncing the sun's energy back into space. But on the other hand, such clouds might reduce rainfall in the Amazon or cause other unintended consequences. Which is the main problem with the whole cloud seeding thing. You can't predict the weather, even if you make it. So more research is needed. So it might not save us from a drought, but could the ocean save us? Julian finds out in this episode here
B1 中級 美國腔 人造云能否将我们从干旱中拯救出来?(Can Man-Made Clouds Save Us From The Drought?) 5 1 joey joey 發佈於 2021 年 04 月 17 日 更多分享 分享 收藏 回報 影片單字