CHARACTERISTICS OF EXTREMES TEMPERATURES IN BUENOS AIRES BY CENTENARY RECORDS. WINTER CONDITIONS STUDY
María Paula Llano y Walter Vargas
Departamento de Ciencias de la Atmósfera y los Océanos. Universidad de Buenos Aires. Buenos Aires, Argentina
CONICET. Buenos Aires, Argentina
Manuscript received on 5th may 2016, in final form on 15th July 2016
The study of climatic conditions in Buenos Aires city has a great importance because of the people living in it. Extreme temperatures present a major impact on the supplying of services which implies the necessity of a diagnosis for various applications. The temperatures series of Buenos Aires Central Observatory have been chosen for this study, for their quality and it have been verified that they represent a large area of influence covering a zone larger than the city. The records used in this work, on some scales cover from mid-nineteenth century up to now and especially from 1909 to 2013 in a daily scale. The evolution of temperatures throughout the century is studied, focusing mainly on the cold periods. A natural state corresponding to the first 20 years of record series is defined where both series do not show a significant linear trend. The cut-off values are defined based on he natural state for studying the different properties of cold semesters. The duration of these as to the maximum temperatures experienced a decrease of 30 days, whereas in the minimum temperatures, of 53 days. The amplitude of the annual harmonics present variations, in the maximum temperatures a negative linear trend is observed, while in the minimum temperatures it is positive. These results are showing the existence of inter-annual variability of the intra-annual variability. The analyses made on the centenarian series allow to reconstruct them as a natural state or an anthropogenic state.