Il Nuovo Cimento C

, Volume 10, Issue 5, pp 517–529 | Cite as

A comparison by stochastic models between present-day and last-century temperatures in udine

  • M. Ceschia
  • R. Garfagnini
  • E. Toppano
Article
  • 11 Downloads

Summary

In this paper the daily average temperatures recorded in Udine in the years 1868, 1869, 1870, 1871, 1876, 1980, 1981, 1984 and 1985 (for which an integral set of reliable and comparable-data was at our disposal) have been analysed. The main purposes of this work are: look for characteristic periodicities in the series of data, analyse the background erratic component by means of stochastic methods and look for possible differences between the temperatures of the last century and those of the present. A linear model of the AR (autoregressive) type of the second order has been determined which represents fairly well the residual series of the daily temperatures for single years after subtracting the seasonal component. The present analysis, at least for the years examined, does not exibit particular results proving a difference between the last-century and present-day temperatures. Finally, a standard year for temperature has been also proposed.

PACS.92.60

Meteorology 

Riassunto

In questo lavoro si analizzano, per mezzo di modelli stocastici, le temperature medie giornaliere registrate a Udine negli anni 1868, 1869, 1870, 1871, 1876, 1976, 1980, 1981, 1984, 1985 (anni per i quali esiste una serie completa ed affidabile di dati). Le principali finalità di questo lavoro sono: la ricerca di periodicità caratteristiche nelle serie di dati, lo studio del fondo erratico mediante le tecniche di analisi dei processi stocastici di tipo ARMA e la ricerca di eventuali differenze tra le temperature attuali e quelle del secolo scorso. Un modello lineare di tipo AR (autoregressivo) del secondo ordine è in grado di rappresentare con buona approssimazione la serie residua delle temperature medie giornaliere ottenuta, per i singoli anni, sottraendo dai dati originali la componente stagionale. I risultati dell'analisi non consentono però di evidenziare macroscopiche differenze tra le temperature dell'altro secolo e quelle attuali. Infine si propone un anno tipo per l'andamento della temperatura.

Резюме

В этой статье анализируются среднеуточные темперауры, зарегистрированные в Удине в 1868, 1869, 1870, 1871, 1876, 1976, 1980, 1981, 1984 и 1985 гг. Основные цели работы: поиски характерных периодичностей в последовательностях данных, анализ фоновой случайной компоненты с помошью стохастических методов и поиски возможных различий между температурами в прошлом веке и в настолщее время. Предлагается линейная модель авторегрессивного типа второго порядка, которая довольно хорошо описывает остаточные последовательности суточных температур для отдельных годов, после вычитания сезонных компонент. Проведенный анализ, по, крайней мере, для исследованных годов не обнаруживает различий между температурами в прошлом веке и в настоящее время. В заключение, приводятся температуры для для стандартного года.

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Copyright information

© Società Italiana di Fisica 1987

Authors and Affiliations

  • M. Ceschia
    • 1
  • R. Garfagnini
    • 1
  • E. Toppano
    • 1
  1. 1.Istituto di Fisica dell'UniversitàUdine

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