|MadSci Network: Earth Sciences
The meteorological equator is shifted north of the equator much of the time over much of the globe. Marked by the Intertropical Convergence Zone (ITCZ), it is north of the equator during the northern hemisphere summer months and moves south of the equator only in some areas during the southern hemisphere summer. This asymmetry arises from the fact that there is greater land mass in the northern hemisphere. The heat capacity of water is greater than that of land so on average the oceans are warmer. The greater land mass leads to a colder mean temperature in the northern hemisphere. This in turn means there is more atmosphere in the northern hemisphere...more mass. As this mean mass shifts southward with the moving ITCZ, it causes the Earth to wobble, an effect called the Chandler oscillation.
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