The analysis of the occurrence of tropical nights in Knjaževac (Eastern Serbia)

• Main Author: Tasić Ana
• Format: Article
• Language: English
• Published: Serbian Geographical Society 2016-01-01
• Series: Glasnik Srpskog Geografskog Društva
• Subjects: tropical nights; trend; air temperature; Serbia; Knjaževac
• Online Access: http://www.doiserbia.nb.rs/img/doi/0350-3593/2016/0350-35931601056T.pdf

Tropical nights are, as defined, days when the minimum temperature does not fall below 20°C. Apart from being of interest for climate scientist, these days also impact the comfort of life of the local population. The paper analyzes the occurrence of tropical nights in Knjaževac, situated at the foothill of the mountain in Eastern Serbia. The research is based on the time series from the measuring station of the Republic Hydrometeorological Service of Serbia and it covers the period of 60 years, from 1955 to 2014, with 50 years of observations. Data were analyzed using standard statistical methods and modelled using simple linear regression. Quantitative data are given in Histogram, showing the frequency of the occurrence of tropical nights both for the whole period and the sub-periods of ten annual observations. Analysis shows that the number of tropical nights in the observed period has a trend of slight increase. In total, 33 days with tropical night were recorded, which occurred in June, July, August and September. Year 2007 is identified as a peak of data sequence, reaching 11 occurrences of tropical nights. In this year the highest ever temperature in Serbia was recorded - of 44.9°C in Smederevska Palanka, whereas maximum temperature in Knjaževac reached 43.5°C, which also represents the record.