Educational Objective

Students will understand how latitude and season

affect duration of insolation.

PurposeThe purpose of this long term investigation is to use the internet to collect and organize latitude, date and duration of insolation data to help generalize the relationship between latitude, season and duration of insolation.

ProcedureGoogle Earth will be used to locate various cities, towns or villages on approximately similar longitudes but widely different latitudes.

Students will then use internet resources to find and record sunrise and sunset times for each location.

ProcedureStudents will then analyze their collected data to generalize how duration of insolation changes with changing latitude and season.

MaterialsComputer Lab – this long term investigation should be introduced in a computer lab so that students can see how to initialize and use Google Earth and cnn.com to gather and record the necessary data.

MaterialsComputers with Excel or some comparable spreadsheet program, Google Earth, and internet access.

DataSeason

Summer Fall Winter Spring

Latitude Duration Latitude Duration Latitude Duration Latitude Duration

GraphLatitude vs. Duration of Insolation

-90

-70

-50

-30

-10

10

30

50

70

90

Summer Fall Winter Spring

Time (Hours)

Lat

itu

de

ResourcesLatitude and Longitude for Selected Cities: http://www.bcca.org/misc/qiblih/latlong_oc.html

Sunrise and Sunset Data: http://aa.usno.navy.mil/data/docs/RS_OneYear.php

Spreadsheet Latitude Lookup: http://www.vcaa.vic.edu.au/prep10/csf/support/sampleunits/SolarHouseDaylight.xls

Earth and Sun Viewer: http://www.fourmilab.ch/cgi-bin/Earth/action?opt=-p

Questions1. What is the relationship between latitude and duration of insolation?2. Compare and contrast seasons in the northern and southern hemispheres.3. How are the Arctic and Antarctic Circles significant in studying duration of insolation?4. How are the Tropics significant?5. How does duration of insolation change at the Equator over the course of the year?6. What resource(s) proved to be most helpful and why?

Scoring Rubric