ATM OCN (Meteorology) 100

WEB ACTIVITY for Homework 2

Fall 1999 Lecture 2

Date Due: Monday, ?? September 1999

BACKGROUND

BACKGROUND

Have you ever needed to know when the sun would set in your town? Knowledge of the time of sunset or sunrise may be needed for planning purposes, for legal matters or for scientific investigations. The local times of sunrise and sunset for each day of the year are provided by many almanacs and appear in the media, such as in the newspapers or on television. These times are defined as the instant when the top of the solar disk is just at the local level horizon. They can be calculated for any place using well known angular relationships that take into account the latitude of the observer (how far one is from the equator in angular measure) and the day of the year (which essentially describes the seasonal course of the tilt of the earth's spin axis with respect to the sun). The U.S. Naval Observatory has prepared sunrise-sunset tables for over 200 locations throughout the country. Inspecting these tabulations reveals several interesting features described below. An on-line, interactive service is available that allows you to determine the times of sunrise or sunset for individual days or the entire year at most cities in the United States.

ASSIGNMENT

For Madison, Wisconsin -- The sun will set today ______________ (please date) at ___________________ (time).
(Note that the table is in standard time, so add one hour for daylight time)

The earliest sunset of the year in Madison is about what date _____________________?
The latest sunrise of the year in Madison is about what date _____________________ ?
The latest sunset of the year in Madison is about what date _____________________ ?
The earliest sunrise of the year in Madison is about what date _____________________ ?
The times of sunrise and sunset on the spring equinox (21 March) is _______________ and ________________.

Last revision: 13 September 1999

URL Address: aos100/homework/f99hmk2k.htm