The sun\'s noon altitude is a relative indicator of the intensity of solar radia

Question

The sun's noon altitude is a relative indicator of the intensity of solar radiation received at the earth's surface. The change in intensity (i.e., noon altitude of the sun) throughout the year is determined by the inclination of the earth's axis to the plane of the ecliptic as the earth revolves around the sun. Two formulae can be used to determine the sun's noon altitude. Use the first for an observer in the winter hemisphere; the second applies when the observer is in the summer hemisphere. On the equinoxes, both formulae work, where: A is the sun's observed noon altitude in degrees above the horizon; LB_OB is the latitude of the observer; and LB_VB is the latitude where the sun is vertically overhead at noon (the sun's declination). ("| |" means "absolute value." Use positive numbers for LB_db and LB_vb even if they're in the Southern Hemisphere). Determine the noon altitude of the sun on the Ungava Peninsula, northern Quebec, Canada (latitude 6l degree N) for each of the following dates (show your work): the equinoxes: June solstice: December solstice: Determine the noon altitude of the sun at Jambi, on the island of Sumatra, Indonesia (latitude 2 degree S) for each of the following dates (show your work): the equinoxes: June solstice: December solstice: a) During the course of a year, how many days does the sun appear directly overhead (i.e., noon sun altitude 90 degree above the horizon) at these two locations? Ungava Jambi b) Briefly, what can you infer from the previous answers about differences in the seasonality of northern Quebec and Sumatra?

Explanation / Answer

Answer 5:

Remember, canada lies in northern hesmisphere.

As for the equinox, we can any use any formula out of the two:

Therefore, For equinox, LBvb= 00, and LBob= 610N (given)

By putting the values in the formula,

A= 90-I61o+0oI = 90-I61+0oI = 90- 61o= 29o

For June solstice: LBvb= 23.5 North

Therefore, A= 90- I(LBob-LBvb)I = 90- I61-23.5I=90- 37.5= 52.50

For December Solstice : LBvb=23.5 South

Therefore, A= 90-I(LBob+LBvb)I = 90- I(61+23.5)I=90-84.5= 5.5o

Answer 6)

Remember, Indonesia lies in southern hemisphere.

we can approach as same as done in above question

LBob= 20S(given),For equinox, LBvb= 0o,.

Therefore, by putting values, A= 90-I(2+0)I= 90-2= 89o  

For June solstice, LBvb=23.5 S, on putting values in equation of winter hemisphere,

A=90-I(2+23.5)I= 90-25.5= 64.5o

For december solstice. LBvb=23.5 N, therefore, on solving

A= 90-I(2-23.5)I= 90-21.5= 68.5o

Answer 7 a)

As we can see the value of "A" above for given location, we cannot found 90o latitude of sun above the horizon at any of the two locations. However, we found two equinoxes over the year where the duration of day and night are equal on the whole earth.

Answer 7b)

We can infer from the above answers that the seasons are of opposite in nature at both the locations at same time. As the northern quebec are located in northern hemisphere, it suffers summer in june and winter in december whereas, sumatra region suffers winter in june and summer in december.

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