2.6: Length of Day and Insolation vs. Latitude
- Page ID
- 39742
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As you can see, not only do the seasons affect the angle of incoming sunlight, but they also greatly influence the length of the day. This is emphasized in Figure \(\PageIndex{1}\) below, which shows the length of day for several given latitudes.
Figure \(\PageIndex{1}\): Length of day vs. Month for several latitudes. (CC-BY-NC 4.0; Alicia Mullens). Alternative description of image.
Take a look at the monthly variation in day length for each of the latitudes provided in Figure \(\PageIndex{1}\). Each latitude variation can be seen by looking at the amplitude (how high/low the line goes) of the curve.
- The Equator experiences ____________________________ in daylength from season to season while locations at latitude 70°N experience ______________________________ in daylength from season to season:
- Major variation; Practically no variation
- Some variation; Major variation
- Practically no variation; Major variation
- How does the month-to-month variation in daylength change with latitude?
- The variation becomes smaller with higher latitude
- The variation becomes larger with higher latitude
- There is no variation with latitude
Total Insolation
Seasonal changes in The Angle of Insolation along with The Length of Daylight ultimately result in seasonal variations in Insolation received at a latitude, as shown in Figure \(\PageIndex{2}\). This is what ultimately affects how temperatures change with seasons.
- As you travel North from the Equator, the seasonal variation in Insolation:
- Becomes Greater
- Becomes Smaller
- Does not Change
- While all other latitudes have one peak in Insolation in June, The Equator has two peaks, which occur in:
- June and December
- March and September
- March and December
- September and June
- What is interesting, is that during the Month of June, the North Pole (90°N) receives _________________ sunlight than the equator.
- More
- Less
We know that with higher latitudes, the angle of insolation becomes lower, so based on what was covered earlier in this investigation, we can conclude that the biggest cause for these latitudes receiving more sunlight than the equator is the length of the day; granted, the sun may be low on the horizon during polar summer, but if the sun is out all 24 hours of the day, that grants a major opportunity for tremendous amounts of warming. As such, polar regions experience tremendous differences in temperature from winter to summer, whereas tropical regions may experience a small, if even noticeable change in temperature from winter to summer.