Beginning of spring
The beginning of spring or the beginning of spring , i.e. the beginning of the spring season , can primarily be determined astronomically , by religious determination , meteorologically or phenologically (according to the development status of the plants).
Northern hemisphere
Astronomic
Astronomically , spring in the northern hemisphere is determined by the primary equinox , the first equinox of the calendar year. The sun is then exactly in the vernal equinox of the earth's orbit. The calendar entry time varies and falls on March 19, 20 or 21 , depending, among other things, on the distance to the last leap year and the time zone .
For details see → Equinox and Season .
Meteorological
For meteorological statistics , the beginning of spring in the northern hemisphere is at the beginning of a month, as in all seasons , here on March 1st. The “meteorological beginning of spring” was determined by the World Meteorological Organization (WMO), a sub-organization of the UN . So three months are assigned to the seasons. December, January and February are the winter months, spring includes - meteorologically speaking - the months of March, April and May and summer the months of June, July and August. In this way, statistics (such as monthly averages) and climate comparisons can be created and compared more easily.
Religious
In several religions, spring festivals celebrate the equinox before the respective summer. Since the First Council of Nicaea in 325, Christians set the beginning of spring to be March 21st as part of the setting of the date of Easter . In the Iranian cultural area and in Baha'itum , Nouruz is celebrated as the New Year and Spring Festival on March 20 or 21. Holi is the Indian spring festival that comes from Hindu tradition on the first full moon day of the month of Phalgun (February / March). The Chinese Spring and New Year Festival , traditionally celebrated over 15 days according to the Chinese calendar, begins on New Year's Day, which falls on a new moon between January 21 and February 21.
Phenological
more pictures
in the sister project Commons to Salix caprea in the Hockenheimer Rheinbogen .
Phenologically , spring in Central Europe is divided into three phases:
- Early spring: From the beginning of flowering of the snowdrops and hazelnuts until the pussy willow are pollen yellow.
- First spring: from the beginning of flowering of the forsythia and leaves of the gooseberry to the beginning of flowering of the pear trees .
- Full spring: From the beginning of flowering of the apple trees and the lilac to the beginning of flowering of the mountain ash and the meadow foxtail .
The phenological beginning of spring changes not only according to the geographical longitude and latitude, but also according to the altitude, the major climatic areas and the small-scale climatic conditions. The individual spring phases in sheltered locations in cities often start much earlier than in the open fields.
Spring moves slowly up the slopes in the mountainous region, being earlier on the southern slopes than on the northern slopes.
Full spring begins in Europe in south-west Portugal near Faro at the end of February and continues to the north-east, where it reaches Germany on April 20 with the Upper Rhine Plain .
(photo from March 19, 2016),
Satakari island in Bottenwiek , northern Baltic Sea off Ii .
Then he moves quickly in the flat country to Finland , which he reached at the end of May. He needs about 90 days for the distance of about 3600 kilometers. So it moves through Europe at an average speed of 40 kilometers per day. The migratory birds follow this : they arrive according to a clear schedule. Star and white wagtail herald the early spring, swifts and nightingales return in the last days of April, although there are also early arrivals. Migratory birds return earlier in the south, in Scandinavia they arrive later, and this has also been documented for the cuckoo . The migratory birds are seen as heralds of spring because the bird calls can now be heard again in nature.
In the beginning of spring, waterfalls in the Alps swell due to the melting of snow , which are inconspicuous in summer or disappear completely.
The time of the phenological beginning of spring changes from year to year; apparently there is a tendency for spring to start earlier in Europe. An indication of this is that numerous species of migratory birds are a few days earlier than z. B. return from their winter quarters in 1970. Global warming is believed to be the cause of the early onset of spring .
For the calculation of the Easter date , March 21st is always used as the beginning of spring.
Southern hemisphere
Astronomically , spring in the southern hemisphere is determined by the secondary equinox (secondary equinox). The calendar entry time varies and falls on September 22nd or 23rd , depending, among other things, on the distance to the last leap year .
literature
- Christian Seiffert, Richard Keller: The garden in the seasons. BLV Verlagsgesellschaft, Munich Vienna Zurich 1983, ISBN 3-405-12835-8
Web links
- Campaign apple blossom country Germany at Planet Wissen
- Earth's Seasons , United States Naval Observatory (March 1, 2009 memento in the Internet Archive )
Individual evidence
- ↑ a b The return of the migratory birds , with schedule and sound samples of bird calls, Swiss Ornithological Institute Sempach , accessed on May 1, 2014.