Retreat of glaciers since 1850 doing so due to transient local weather conditions, which have brought more precipitation and cloudier, cooler summers since 2002. Tropical glaciers are located between the Tropic of Cancer and the Tropic of Capricorn, in the region that lies 23° 26′ 22″ north or south of the equator. Strictly, a tropical glacier is located within the astronomical tropics; the area where the annual temperature variation is less than the daily variation, and is within the oscillation area of the Intertropical Convergence Zone. Tropical glaciers are the most uncommon of all glaciers for a variety of reasons. Firstly, the regions are the
Ascendant (Capricorn through Gemini), individual-oriented Ascendants are equally or more common. In the southern hemisphere, long and short ascension are reversed. For instance, at the latitude of Concepción, Chile: At the Arctic and Antarctic circles, at roughly 66½° North and South latitude respectively, a degree of the ecliptic becomes circumpolar. If the sun for example occupies that degree, it will neither rise nor set, but will lie upon the horizon for 24 hours. As we move into higher latitudes, more and more degrees of the ecliptic will neither rise nor set, until at the north pole half of the ecliptic degrees