巴黎上空的夜光云
(原标题: Noctilucent Clouds over Paris)
2022-07-12
浏览次数: 14
这是北方夜光云的季节。夜光云由小冰晶组成，只有在上层大气的特定条件下才会形成，在夏末的日落时分，当阳光从下面照射时，夜光云可能会出现。夜光云是已知的最高的云，现在被确定为从地面观测到的极地中间层云。尽管自2007年以来，美国宇航局的AIM卫星就对夜光云进行了观测，但关于夜光云的许多情况仍然未知，因此这是一个活跃的研究课题。这张特色图片显示了法国巴黎上空飘过的广阔而起伏的夜光云。今年，一些北方地区已经出现了特别生动的夜光云。
查看原文解释
It's northern noctilucent cloud season. Composed of small ice crystals forming only during specific conditions in the upper atmosphere, noctilucent clouds may become visible at sunset during late summer when illuminated by sunlight from below. Noctilucent clouds are the highest clouds known and now established to be polar mesospheric clouds observed from the ground. Although observed with NASA's AIM satellite since 2007, much about noctilucent clouds remains unknown and so a topic of active research. The featured image shows expansive and rippled noctilucent clouds wafting over Paris, France. This year, several northern locations are already reporting especially vivid displays of noctilucent clouds.
© Bertrand Kulik