Auroral morphology

Abstract

A review is made of auroral morphology, defining morphology in the broader sense to be a description of the auroral display. It is seen that there are several classes of displays which for all intents and purposes, may be considered independent. The classes of displays are (1) polar-glow aurora, (2) polar cap aurora (discrete), (3) red auroral arcs, and (4) polar aurora (conventional). The polar auroras have been studied as complete displays by T.N. Davis using statistical methods and by S.-I. Akasofu using individual displays. Davis arrives at a concept for the display as a fixed pattern under which the Earth rotates, while Akasofu believes that the display consists of a system of stable arcs which are disrupted, by as yet unknown forces, from one to several times during a night. The latter appears to be the more promising and one looks forward to the completion of the studies. ДaeTsя oбoзreNиe uTreNNeй мorфoлoгии, чaraкTerизuя мorфoлoгию в бoлee шиroкич raмкaч s Teм, chToбы oNa sлuжилa oпиsaNиeм вызвaNNoй пoляrNым sияNиeм raзвerTки. Пoвидимoмu suщesTвueT Nesкoлькo кaTeгorий raзвerToк, кoTorыe, s любoй Tochки зreNия, мoгuT schиTaTьsя Neзaвиsимыми дruг oT дruгa. КaTeгorии эTи sosToяT из : (1) пoляrNoгo sияNия, (2) sияNия пoляrNoй шaпки, (3) кrasNыч дuг пoлNrNoгo sияNия и (4) пoляrNoгo sияNия (Traдициoииoгo). ПoляrNыe sияNия изuchaлиsь в кachesTвe кoмплeкTNыч raзвerToк T. N. Дэвиsoм, пrимeNявшeгo sTaTиsTиchesкиe мeToды, и s.-И. aкasoфu, иsпoльзuющeгo oTдeльNыe raзвerTки. Дэвиs пrичoдиT к вывoдu, chTo raэвerTкu мoжNo rassмaTrивaTь в видe sTaциoNarNoй диaгraммы, пoд кoToroй вraщaeTsя 3eмля, Toгдa кaк aкasoфu пoлaгaeT, chTo raзвerTкa sosToиT из sиsTeмы sToйкич дuг, raзrывaeмыч oT oдNoгo дo Nesкoлькич raз в TecheNиe, Nochи, дoseлe eщe NeизвesTNыми sилaми. ЭTa Teorия пreдsTaвляeTsя пoвидимoмu бoлee мNoгooбeщaющeй и s иNTeresoм oжидaeTsя зaвerшeNиe изucheNий в эToм NaпraвлeNии.