The weather in Taipei last week was treacherous and changeable — one minute it was pouring, the next the sun was shining. On Thursday afternoon, a resplendent rainbow appeared over the city.
台北市的天氣上週詭譎多變，一下子大雨，一下子放晴，上週四下午還難得出現一道完整的彩虹！
Due to the high elevation of Chinese Culture University (CCU) on Yangmingshan, Taipei, people on the campus enjoy a broad vista of the city. Chou Kun-hsuan and Liu Ching-hwang, professors of CCU’s Department of Atmospheric Sciences, said that this rainbow was clearly visible from 6:57 am to 3:55 pm on Thursday, meaning that it lasted a full eight hours and 58 minutes. Chou says that this rainbow has broken the six-hour world record observed in the UK in 1994, likely setting a world record for longest-lasting rainbow
文化大學校園位於陽明山，地勢高而視野廣闊。該校大氣科學系教授周昆炫及劉清煌觀測到，這道彩虹從週四早上六時五十七分至下午三時五十五分期間均清晰可見，時間長達八小時五十八分。周昆炫認為，這道長壽彩虹已經打破一九九四年在英國所觀測到的六小時彩虹，成為彩虹持續時間最久的世界紀錄。
Every winter, the northeast monsoon affects northeast Taiwan, and eastern Taipei, exposed to these winds, often has heavy rainfall. As the sun migrates west over the course of the day, it shines down on the eastern part of the city. When a sun’s ray hits an airborne water droplet, the ray will be refracted as it enters the droplet, reflected on the interior wall and then refracted once more as it exits. These two refractions and one reflection are what causes the rainbow.
每到冬季東北季風來襲，台北東部山區恰好是迎風面，往往下起大雨；到了下午，太陽西移，台北西邊反而有陽光露臉──這時陽光射到水珠裡，經過兩次折射、一次反射，就會出現彩虹。
Chou said that the rainbow in fact consists of four layers — in addition to the more obvious “rainbow” and its outer periphery, referred to as the “secondary rainbow,“ which is fainter than the rainbow itself and with some colors appearing in reverse order, there are also two “supernumerary rainbows” that are less distinct because of their size and location.
Source article: http://www.taipeitimes.com/News/lang/archives/2017/12/06/2003683483