Effect of autocorrelation on temporal trends in air-temperature in Northern Algeria and links with teleconnections patterns

Abstract

This study investigates the effect of autocorrelation on temporal trends and step change on monthly, seasonal and annual temperatures of six meteorological stations of the North of Algeria from 1950 to 2016. Afterwards, links between the general atmospheric circulation, via six climate indices, and temperature are examined. Trends of temperature are analysed using six different versions of the Mann Kendall approach while the step change of the time series is computed using the original Pettitt test and the modi ed-Pettitt. Statistical tests have shown an increase in annual temperatures from 0.8 to 0.9°C since the 1980's on the coastal regions and 90's on the highlands. This warming most often exceeds 1°C on a seasonal scale, particularly in summer, while no signi cant trend is observed in winter. On a monthly scale, the increase in temperatures is marked between April and October. The analysis of relationships between six climate indices and average temperatures has shown that inter-annual temperature variability is most often associated with the East Atlantic oscillation for the entire study area. Winter temperatures are in uenced by the Mediterranean oscillation as well as the North Atlantic oscillation. The East Atlantic oscillation is the dominant mode of circulation in spring and summer, while in autumn temperatures are strongly linked to West Mediterranean Oscillation. However, no signi cant correlations have been observed between temperatures and the Arctic Oscillation and El Nino southern oscillation. StationsLatitude Longitude Altitude (m) Study period Algiers

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