A Class of Indices and a Graphical Tool to Monitor Temperature Anomalies

Abstract

We propose a graphical device—Three I’s of Anomalies (TIA) curves—that provides information on the incidence, intensity, and inequality (variability) of air temperature anomalies. We also propose a class of indices that help to compare different TIA curves when visual inspection alone is inconclusive. This class of indices identifies the 3 dimensions of anomalies and can be decomposed to evaluate air temperature anomalies according to different characteristics. Moreover, the results from this class of indices are consistent with the graphical device. We calculated TIA curves and a class of indices to analyze temperature anomalies in Málaga, Spain, from 2000 to 2017. Comparison of sequential 5-year periods indicated that maximum and minimum temperature anomalies have generally increased in frequency and intensity over time. The proposed index, which considers all dimensions, indicated that maximum and minimum temperature anomalies have increased. Analysis of different geographical areas indicated that inland areas had the greatest anomalies for minimum temperatures and mountainous areas had the greatest anomalies for maximum temperatures. Inland areas also had a stronger pattern of increasing anomalies. The coastline, especially in the western region, had weaker maximum and minimum temperature anomalies.