Homework 3: Atmospheric and Ocean Circulation
HAND-IN DURING CLASS ON WEDNESDAY 11TH FEBRUARY
Review questions:
1)
(i)
(ii)
(iii)
What is the Intertropical Convergence Zone (ITCZ) and what is the
weather like at the ITCZ?
[5 points]
What ultimately happens to air that rises at the ITCZ and why?
[4 points]
Why doesn’t the ITCZ follow a perfect circle of latitude parallel to the
equator or on the equator?
[4 points]
2)
(i)
(ii)
(iii)
Briefly describe the Coriolis effect.
[3 points]
Given your answer to (i), explain the motion of the winds around a low
pressure zone in the northern hemisphere.
[2 points]
Sometimes low pressure zones develop near the equator when the ITCZ
intersects the equator. However, cyclones (which are characterized by
winds flowing around an area of low pressure) never develop within 5
degrees of the equator. Why not? (Hint: Read the last paragraph
describing the Coriolis effect on p.63 of the textbook). [3 points]
3) Overleaf is a map of India. Look at the inset to see the overall physiographic
regions and then locate the major mountain ranges on the bigger map. Sketch a
simplified map of India. Shade the areas in India that you think would have
particularly high rainfall and the areas you think would have low rainfall during the
monsoonal season, June-July. Explain your reasoning. (To help, have a look at
winds on Fig. 4-21 in the textbook. Also you can download a color version of the
India map at the class website if you want to view the color-scale for the
topography.)
[8 points]
Map of India
4) (i) What is meant by the term thermohaline conveyor belt?
(ii) In what ways is it important for the biosphere?
[4 pts]
[4 pts]
5) At the end, you will find two pictures of the Earth seen from a satellite positioned
above the Earth at 35800 km distance, such that almost half of the Earth’s surface
can be seen. The first picture (A) is a picture taken in the visible spectrum, i.e. an
ordinary photograph. The second picture (B) is taken in the infrared at a
wavelength of 6 µm. At this wavelength water vapor is opaque. In picture B the
color is artificial: the warmest areas are dark and the coldest white. Thus, dark
areas represent regions in which the upper troposphere is dry so that radiation from
lower, warmer layers is able to reach the satellite; white areas correspond to
radiation from the upper troposphere, which is cold. By comparing B with A,
identify the following features:
(i)
cumulonimbus cloud formations associated with the ITCZ
(ii)
the northern and southern polar fronts
(iii) the subtropical high pressure regions
Label these places on image B, which you hand in with your homework answers.
[8 points]
A: Visible image of Earth.
B: Picture of Earth at 6 microns. This picture shows the same view of the Earth as A.