美国内布拉斯加州上空的乳状云

美国内布拉斯加州上空的乳状云

ByNASA中文

2023年2月12日 Mammatus Clouds over Nebraska Image Credit & Copyright: Jorn Olsen Photography Explanation: When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. The mammatus clouds pictured here were photographed over Hastings, Nebraska during 2004 June. Tomorrow’s picture: comet mars 美国内布拉斯加州上空的乳状云 图像提供与版权:…

落日时分远离的雷暴云

落日时分远离的雷暴云

ByNASA中文

2022年1月16日 A Retreating Thunderstorm at Sunset Image Credit & Copyright: Alan Dyer (The Amazing Sky) Explanation: What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end. Taken in mid-2013 in southern Alberta, Canada, the cloud is moving to the east, into the distance, as the sun sets in the west, behind the camera. In the featured image, graphic sunset colors cross the sky to give the already photogenic cloud striking orange and pink hues. A darkening blue sky covers the background. Further in the distance, a rising, waxing, gibbous moon is visible on the…

加拿大萨斯喀彻温省上空的乳状云

加拿大萨斯喀彻温省上空的乳状云

ByNASA中文

2021年8月11日 Mammatus Clouds over Saskatchewan Image Credit & Copyright: Michael F Johnston Explanation: When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. The mammatus clouds pictured here, lasting only a few minutes, were photographed over Regina, Saskatchewan, Canada, just after a…

美国拉什莫尔山上空的乳状云

美国拉什莫尔山上空的乳状云

ByNASA中文

2020年12月07日 Mammatus Clouds over Mount Rushmore Image Credit & Copyright: Laure Mattuzzi Explanation: What’s that below those strange clouds? Presidents. If you look closely, you may recognize the heads of four former US Presidents carved into famous Mount Rushmore in South Dakota, USA. More obvious in the featured image are the unusual mammatus clouds that passed briefly overhead. Both were captured together by a surprised tourist with a quick camera in early September. Unlike normal flat-bottomed clouds which form when moist and calm air plateaus rise and cool, bumpy mammatus clouds form as icy and turbulent air pockets sink and heat up. Such turbulent air is frequently accompanied by a thunderstorm. Each mammatus lobe spans about one kilometer. The greater mountain is known to native…