Answer to Question 1The intertropical convergence zone (ITCZ) is in the equatorial region where the
surface winds of two Hadley cells converge. Strong heating in the ITCZ causes
surface air to expand and rise. The humid, rising, expanding air loses moisture as
rain, some of which contributes to the success of tropical rainforests. Because the
Northern Hemisphere contains much less ocean surface than the Southern
Hemisphere and because landmasses have a lower specific heat than the ocean,
seasonal differences in temperature and cell circulation are more extreme in the north.
Another consequence of the markedly different proportions of land to ocean surface
in the two hemispheres is the position of the ITCZ. The convergence zone does not
coincide with the geographical equator (0 latitude). Instead, it lies at the
meteorological equator (or thermal equator), an irregular imaginary line of thermal
equilibrium between the hemispheres, situated about 5 north of the geographical
equator. The positions of the meteorological equator and the ITCZ generally
coincide. They change with the seasons, moving slightly farther north in the northern
summer and returning toward the equator in the northern winter. Monsoons are linked
to the different specific heats of land and water and to the annual northsouth
movement of the ITCZ. The intensity and location of monsoon activity depend on the
position of the ITCZ. The monsoons follow the ITCZ south in the Northern
Hemispheres winter and north in its summer.
Answer to Question 2Sunlight striking polar latitudes spreads over a greater area (that is, polar areas
receive less radiation per unit area) than sunlight at tropical latitudes. Near the poles,
light also filters through more atmosphere and approaches the surface at a low angle,
favoring reflection. Polar regions receive no sunlight at all during the local winter. By
contrast, at tropical latitudes, sunlight strikes at a more nearly vertical angle, which distributes the same amount of sunlight over a much smaller area. The light passes
through less atmosphere and minimizes reflection. Tropical latitudes thus receive
significantly more solar energy than the polar regions, and mid-latitude areas receive
more heat in summer than in winter.
Pupil Assessment, Starting Position with Penlight to Side of Pupil
The surgical nurse assists the client into the correct position
Position of the fetus in late pregnancy results in stresses on the mother’s body.
Genes expression due to position
Genes expression due to position
Position effect variegation of eye color in Drosophila