Portfolio

Shortest Day--Shortest Night

May 10, 1976 / T. Neil Davis

Why, asks Mr. Jim Schneider of KUAC, is the shortest day longer than the shortest night?

Looking over sunrise-sunset times, he noticed that the shortest night (June 21) at Fairbanks is only 2 hours, 11 minutes long, but the shortest day (December 21) is 3 hours, 42 minutes.

Were it not for refraction of the sun's rays in the atmosphere, the shortest day would equal the shortest night at a particular latitude. Atmospheric refraction bends the rays so that they can pass over the horizon. Hence, the sun appears to rise before it actually reaches the horizon and it is still visible at night after it is actually below the horizon. Consequently, every day is longer than it would be if there were no refraction.

About

Since it was established by an Act of Congress in 1946, scientists at the Geophysical Institute have studied geophysical processes from the center of the Earth to the surface of the sun and beyond, turning data and observations into information useful for state, Arctic and national priorities.

Contact info

The GI is located on the West Ridge of the University of Alaska Fairbanks campus.

2156 Koyukuk Drive
University of Alaska Fairbanks
Fairbanks, AK 99775

We acknowledge the Alaska Native nations upon whose ancestral lands our campuses reside. In Fairbanks, our Troth Yeddha' Campus is located on the ancestral lands of the Dena people of the lower Tanana River.

The University of Alaska Fairbanks is an Affirmative Action/Equal Opportunity employer, educational institution and provider and prohibits illegal discrimination against any individual: Learn more about UA's notice of nondiscrimination.

UA is committed to providing accessible websites. Learn more about UA’s notice of web accessibility.

Please report any problems or feedback concerning this website to uaf-rcs@alaska.edu.

©2024 Geophysical Institute, University of Alaska Fairbanks.