Swell (ocean)

A swell, in the context of an ocean, sea or lake, is a series of mechanical waves that propagate along the interface between water and air and thus are referred to as surface gravity waves. These series of surface gravity waves are not wind waves, which are generated by the immediate local wind, but instead are generated by distant weather systems, where wind blows for a duration of time over a fetch of water. More a swell consists of wind-generated waves that are not—or are hardly—affected by the local wind at that time. Swell waves have a long wavelength, but this varies due to the size and duration of the weather system responsible for the swell and the size of the water body. Swell wavelength varies from event to event. Swells which are longer than 700 m occur as a result of the most severe storms. Swells have a narrower range of frequencies and directions than locally generated wind waves, because swell waves have dispersed from their generation area, have dissipated and therefore lost an amount of randomness, taking on a more defined shape and direction.

Swell direction is the direction. It is measured in degrees, referred to in general directions, such as a NNW or SW swell. Large breakers observed on a beach may result from distant weather systems over a fetch of ocean. Five factors influence the formation of wind waves which will go on to become ocean swell: Wind speed or strength relative to wave speed – the wind must be moving faster than the wave crest for net energy transfer from air to water. Further exposure to that specific wind could only cause a loss of energy due to the breaking of wave tops and formation of "whitecaps". Waves in a given area have a range of heights. For weather reporting and for scientific analysis of wind wave statistics, their characteristic height over a period of time is expressed as significant wave height; this figure represents an average height of the highest one-third of the waves in a given time period, or in a specific wave or storm system. The significant wave height is the value a "trained observer" would estimate from visual observation of a sea state.

Given the variability of wave height, the largest individual waves are to be somewhat less than twice the reported significant wave height for a particular day or storm. Wind waves are generated by many kinds of disturbances such as seismic events and crossing wind; the generation of wind waves is initiated by the disturbances of cross wind field on the surface of the water. Two major mechanisms of surface wave formation by winds and other sources of wave formation can explain the generation of wind waves. However, if one set a flat water surface and abrupt cross wind flows on the surface of the water the generation of surface wind waves can be explained by following two mechanisms which are initiated by normal pressure fluctuations of turbulent winds and parallel wind shear flows. 1) Starts from "Fluctuations of wind": the wind wave formation on water surface by wind is started by a random distribution of normal pressure acting on the water from the wind. By the mechanism developed by O. M. Phillips, the water surface is at rest and the generation of wave is initiated by adding turbulent wind flows and by the fluctuations of the wind, normal pressure acting on the water surface.

This pressure fluctuation arise normal and tangential stresses to the surface water, generates wave behavior on the water surface. 2) Starts from "wind shear forces" on the water surface. He found the energy transfer from wind to water surface as a wave speed, c is proportional to the curvature of the velocity profile of wind Ua’’ at point where the mean wind speed is equal to the wave speed. Since the wind profile Ua is logarithmic to the water surface, the curvature Ua’’ have negative sign at the point of Ua=c; this relations show the wind flow transferring its kinetic energy to the water surface at their interface, arises wave speed, c. the growth-rate can be determined by the curvature of the winds at the steering height for a given wind speed Ua. These wave formation mechanisms occur together on the ocean surfac

Knights of Columbus Vatican Film Library

This article is about the microfilm library in St. Louis, Missouri. For the motion picture archive in Rome, see Vatican Film Library The Knights of Columbus Vatican Film Library in St. Louis, Missouri is the only collection, outside the Vatican itself, of microfilms of more than 37,000 works from the Biblioteca Apostolica Vaticana, the Vatican Library in Europe, it is located in the Pius XII Memorial Library on the campus of Saint Louis University. The Library was created with funding from the Knights of Columbus; the goal was to make other documents more available to researchers in North America. Microfilming of Vatican manuscripts began in 1951, according to the Library's website, was the largest microfilming project, undertaken up to that date. From 1951 to 1957, twelve million manuscript pages were recorded, from 30,000 different works; this represents 75% of the manuscripts available in the targeted language groups. Other microfilm projects in the 1950s included Jesuit archival material from Rome, archives in both North America and South America, the Philippines.

The Library opened in 1953, moved to the St. Louis University campus, in the Pius XII Memorial Library, in 1959; the first librarian was Charles J. Ermatinger, who served until 2000; as of 2007, the Library has microfilmed versions of over 37,000 manuscripts, with material in Greek, Arabic and Ethiopic, as well as several more common Western European languages. There are reproductions of many works from the Biblioteca Palatina and Biblioteca Cicognara at the Vatican, as well as Papal letter registers from the Archivio Segreto Vaticano from the 9th to 16th centuries, in the series Registra Vaticana and Registra Supplicationium; the Film Library collects manuscript catalogs and handwritten inventories of Vatican Library manuscripts, as well as those of other libraries, including a collection of microfilmed copies of over 2,500 medieval and renaissance manuscripts from other libraries, over 20,000 incunabula, 52,000 color slides of illuminated manuscripts. The collection includes many hardcopy works on the subjects of palaeography, codicology and other topics related to manuscript studies.

The Library hosts an annual conference on Manuscript Studies, held in St. Louis in mid-October. Since 1957, the Library has published a twice-annual journal, which focuses on manuscript studies of medieval and Renaissance documents, it is published through Brepols Publishers

Son of a Trickster

Son of a Trickster is a 2017 coming of age novel by Eden Robinson. In it, a teenage boy wades through the complications of a broken family, social pressure, drugs and poverty and discovers the Haisla trickster Wee'jit; the story is set in Kitimat, British Columbia. It took eight years to write. In 2018, Robinson released the second book in Trickster Drift. Filmmaker Michelle Latimer and Streel Films have secured rights to adapt the book into a TV series, slated to premiere on CBC Television in 2020; the novel was selected for the 2020 edition of Canada Reads, in which it will be defended by actress Kaniehtiio Horn. 2017 Giller Prize shortlist 2018 BC Book Prizes - Ethel Wilson Fiction Prize shortlist 2018 Ontario Library Association’s Evergreen Award shortlist 2018 Sunburst Award shortlist