meteorology Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...

, a singularity is a

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmo ...

phenomenon likely to occur with reasonable regularity around a specific approximate calendar date, Barry R.G. & Chorley R.J. (1987), ''Atmosphere, Weather & Climate'', 5th ed, Routledge, outside of more general seasonal weather patterns (e.g., that

May Day May Day is a European festival of ancient origins marking the beginning of summer, usually celebrated on 1 May, around halfway between the Northern Hemisphere's March equinox, spring equinox and midsummer June solstice, solstice. Festivities ma ...

is usually warmer than

New Year's Day In the Gregorian calendar, New Year's Day is the first day of the calendar year, January 1, 1 January. Most solar calendars, such as the Gregorian and Julian calendars, begin the year regularly at or near the December solstice, northern winter ...

northern Northern may refer to the following: Geography * North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating ...

locales). The existence of singularities is disputed, some considering them due to seeing patterns in

noise Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrat ...

and statistical artifacts from small samples. In North America, the most significant purported singularities are

January thaw January is the first month of the year in the Julian and Gregorian calendars. Its length is 31 days. The first day of the month is known as New Year's Day. It is, on average, the coldest month of the year within most of the Northern Hemispher ...

(warmer weather around January 25) and

Indian summer An Indian summer is a period of unseasonably warm, dry weather that sometimes occurs in autumn in temperate regions of the northern hemisphere. Several sources describe a true Indian summer as not occurring until after the first frost, or mor ...

(warmer weather in mid-autumn). More fanciful ones include the British tradition that rain on St. Swithun's Day (15 July) will be followed by forty days and nights of rain, and similar folk beliefs around

Groundhog Day Groundhog Day (, , , ; Lunenburg County, Nova Scotia, Lunenburg, Nova Scotia: Daks Day) is a tradition observed regionally in the United States and Canada on February 2 of every year. It derives from the Pennsylvania Dutch superstition that if ...

Studies

Although folk tales such as St Swithun's Day generally have little credibility, some of these events have a more solid basis. Early scientific investigation involved the creation of calendars of singularities based on temperature and rainfall anomalies. Later and more successful work by

Hubert Lamb Hubert Horace Lamb (22 September 1913 in Bedford – 28 June 1997 in Holt, Norfolk, Holt, Norfolk) was an English climatologist who founded the Climatic Research Unit in 1972 in the School of Environmental Sciences at the University of East A ...

of the

Climatic Research Unit The Climatic Research Unit (CRU) is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change. With a staff of some thirty research scientists and s ...

was based on air circulation patterns. Lamb's work analysed the daily frequency of airflow categories between 1898 and 1947. Similar work was carried out by Flohn and Hess in central Europe based on analysis of air flows from 1881 to 1947. A 1955 study by Liverpool Observatory and Tidal Institute analysed maximum daily temperatures at a single location from 1900 to 1953. This found problems when attempting to demonstrate the statistical significance of apparent temperature anomalies. In the 1950s, E.G. Bowen suggested that some rainfall calendar cities might be explicable in terms of meteoric particles from cometary orbits acting as ice nuclei in terrestrial clouds; his theory received support from a number of sources. However, such work has now fallen out of favour due to modern dynamic modelling techniques, although articles are still being written reflecting an interest in the topic.

References

External links

Singularities
developed for the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

* {{DEFAULTSORT:Singularity (Climate) Climatology