Purpose: This lab exercise has been designed to acquaint thestudent with the relative importance of the various results of theEarth – Sun geometric relationship. Formulae The Sun’s altitudeabove the horizon may be determined by; h = 90o-Alat where, h = theSun’s noon altitude at a given latitude Alat = absolute value ofdifference between sub-solar point and latitude under considerationThe following table lists values for insulation, altitude, andhours of day length. The subscripts s and w refer to conditions atsummer and winter solstices respectively.

Questions

1. Complete the table by filling in the missing values.

2. On the accompanying graph sheet plot AJ, AD, and AH againstlatitude.

3. Why is the insolation difference negative at the equator,even though the sun’s elevation and daylength are the same on bothsolstices? i.e. why is the is the insolation somewhat greater onDecember 22 than on June 22?

4. Between the equator and about 30° N, which effect seems todominate to produce seasonal differences in insolation – thevariation of daylength or the variation of the sun’s altitude.Comment on the amount of seasonal difference near the equator.

5. North of 60° which effect is more important in producingseasonal differences in insolation?

6. How would the seasonal temperature differences change withlatitude, i.e. does seasonality change with latitude?

7. Why would a large winter to summer temperature contrast occurat 40° N?

8. During the summer solstice, which latitude would probablyhave the greatest surface temperatures? why?

The following table lists values for insulation, altitude, andhours of day length.