[:ja]今週最後の画像はアレックス・ゲルスト宇宙飛行士がISSから撮影した夜光雲です。
夜光雲は極中間圏雲(polar mesospheric clouds, PMC)とも呼ばれ、地上80km付近の中間圏にできる特殊な雲で、日の出前や日没後に観測される気象現象です。地球上で最も高い高度に発生する雲と言われます。夏になっている北・南どちらかの半球の高緯度地域で多く発生します。通常の雲が地上~10km付近にできるのに対し、夜光雲は地上約75~85kmの中間圏界面付近にできます。高度の高い位置に発生するため、太陽が地平線付近にあるとき下から日が当たり、青白く輝いて見えます。
地上から見た夜光雲はこちらです。
参考文献： XXX’s Tweet
ウェブ地球儀で地球俯瞰画像を見る： LiVEARTH
[Earthview Wonders] No.558: Noctilucent Clouds
This week ends with the noctilucent clouds captured by astronaut Alex Gerst on board ISS.
Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. They consist of ice crystals and are only visible during astronomical twilight. They are most often observed during the summer months at high-altitude areas. They are the highest clouds in Earth’s atmosphere, located in the mesosphere at altitudes of around 75-85km. They are too faint to be seen in daylight, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in Earth’s shadow.
The noctilucent clouds captured from the ground is as follows.
Reference: Alex Gerst’s Tweet
See earthview photo gallery with web-globe: LiVEARTH[:en][Earthview Wonders] No.558: Noctilucent Clouds
This week ends with the noctilucent clouds captured by astronaut Alex Gerst on board ISS.
Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. They consist of ice crystals and are only visible during astronomical twilight. They are most often observed during the summer months at high-altitude areas. They are the highest clouds in Earth’s atmosphere, located in the mesosphere at altitudes of around 75-85km. They are too faint to be seen in daylight, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in Earth’s shadow.
The noctilucent clouds captured from the ground is as follows.
Reference: Alex Gerst’s Tweet
See earthview photo gallery with web-globe: LiVEARTH[:]