IGNIS Spring 2016 | Page 4

SPRING I wandered lonely as a cloud That floats on high o'er vales and hills, When all at once I saw a crowd, A host, of golden daffodils; Beside the lake, beneath the trees, Fluttering and dancing in the breeze William Wordsworth (1770 - 1850) This year Wordsworth would have been wandering in January as many plants, including daffodils, were fooled by the mild weather and woke up early. If the weather and the plants are doing their own thing, what decides when spring actually begins? Changes of season are measured in different ways. An astronomical season is calculated based on the tilt of the Earth relative to the Sun. Spring starts when the Sun strikes directly onto the equator; when day and night are of equal length (equinox). This varies each year so that the starting date for spring falls on different days in different years. This year spring in the Northern Hemisphere begins on the 20th March and ends 19th June. Meteorologists require consistent data between the years to enable them to analyse patterns, therefore meteorological seasons have set start and finish dates. Spring in the Northern Hemisphere runs from March 1st - May 31st. In the traditional Chinese calendar, the spring season lies between the end of winter (Feb 4th) 4 IGNIS and the beginning of summer (5th May), with the equinox roughly in the middle. Chinese New Year celebrations actually mark the beginning of the spring season. In subarctic areas, spring may not arrive until May or even June, while of course spring in the Southern Hemisphere runs from September to November. In the Celtic tradition, spring is based solely on daylight and the strength of the noonday sun. Beginning in early February (near Imbolc) and continuing until early May (Beltane) this is closer to the way ecologists mark the year. They allow for natural variations in climate by dividing the year into six seasons with no fixed dates. The prevernal (prespring) season lies between winter (hibernal) and spring (v