Imprints of approximately 8 year oscillation in climatic time series

Abstract

Due to activity and complex interaction of various climate-determining agents, a wide range of variability patterns can be found in the meteorological records. Some of these can be attributed to external factors such as changes in solar or volcanic activity; others are linked to internally induced climate variations. Among the perhaps less prominent, yet still potentially influential variability modes is the approximately 8 year oscillation. In the past, its presence has been reported in various (particularly European) climate records, typically related to temperature or pressure data. Here, the presence of the approximately 8y cycle has been investigated in climate signals originating from a range of observational, reanalyzed and simulated datasets. Through statistical techniques based primarily on wavelet transform and regression analysis, magnitude and statistical significance of the approximately 8y oscillation were evaluated, as well as its temporal stability and geographical patterns.