Questa immagine potrebbe avere delle imperfezioni perché è storica o di reportage.
A season is a division of the year marked by changes in weather, ecology, and amount of daylight. On Earth, seasons result from Earth's orbit around the Sun and Earth's axial tilt relative to the ecliptic plane. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations. In temperate and sub-polar regions, four calendar-based seasons are generally recognized: spring, summer, autumn or fall, and winter. Regardless of the time of year, the northern and southern hemispheres always experience opposite seasons. Image taken from page 28: A Class Book of Modern Geography by Albert Hill, 1898.
