time Flashcards
what is UTC?
coordinated unversal time, which uses the time in Greenwich england.
it is 12 hours behind NZST and 13 behind NZDT.
the use of UTC is indicated how?
using the letter Z after the date and time.
what is daylight?
hours between beginning of MCT and the end of ECT
what is MCT?
morning civil twilight when the centre of the rising suns disc is 6 degrees below the horizon
what is ECT?
when the centre of the setting suns disc is 6 degrees below the horizon.
what is night?
end of ECT and beginning of MCT
what is twilight?
at each end of the day, both before the sun has appeared above the horizon and after it has disappeared below the horizon, there’s still daylight left.
what is sunrise?
the instant when the upper edge of the suns disk is level with the ideal horizon.
what is sunset?
the instant when the upper edge of the suns disc is level with the ideal horizon
what are the factors affecting sunrise and set?
latitude and seasons
how does latitude affect sun rise and set?
due to the earths tilted axis the latitudes are at different angles so for the same time, how much daylight you experience depends on what latitude you’re on.
how do seasons affect sunrise and set?
during summer the beginning of MCT is earlier and end of ECT is later. opposite for winter.
insignificant in equatorial regions where the length of the day is more or less equal to length of night, but at the poles its more extreme, daylight lasts 24 hours without no night and then the reverse in winter.
what affects the length of twilight?
sun rises steeply in the tropics so twilight is shorter and as you move away from the equator the sun rises at a flatter angle meaning it takes more time.
what are the three factors affecting daylight conditions?
atmospheric conditions altitude and obstructions.
how do atmospheric conditions affect daylight?
cloud, fog, mist etc serve to reduce the amount of daylight available
