Traditionally the autumn equinox is a celebration of the harvest when summer ends and its fruits are collected in preparation for winter. Yet there are other indicators given by the most ancient sacred sites that mark the autumn equinox.
On the day of an equinox, daytime and nighttime are of approximately equal duration all over the planet. There are the scientific approach developed throughout the ages - astronomical, meteorological, phenological.
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| Digital Art of Robert Jahns |
In astronomy all four seasons start along with the equinoxes and solstices. Before the Southward or September equinox - autumn in the northern hemisphere and spring in the south - the Sun rises and sets more northerly. After the equinox it rises and sets more southerly.
In contrast meteorology divides a year into four seasons - spring, summer, autumn or fall, and winter. Three months for each based on their monthly average temperatures, with summer as the warmest and winter the coldest.
Phenology applies a range of environmental and biological indicators to mark life cycles in periodic events. How the weather and climate influence such events, like leaves falling off trees or birds migrating to warmer countries.
