Methodological approach to the study of the daily persistence of the sea breeze in Alicante (Spain)

Abstract

This study examines the degree of persistence in the sea-breeze in Alicante. This research is based upon the sequence of semi-hourly data for wind direction and speed for the five-year period from 1999 to 2003 (database of sea breeze days). The repetitive behaviour of this meteorological variable (consecutive days with sea breeze winds), is studied by applying various methods and statistical techniques: analysis of the number and length of spells of days with sea breeze; frequency distribution of the sequences according to duration (concentration, or Lorenz, curves); calculation of coefficients of persistence (empirical and conditional probabilities), and probability testing for the duration of the sea breeze spells using one and two-order Markovian chain models (cM1 and cM2). The results demonstrate the high level of persistence of this wind mechanism in the southeast of the Iberian peninsula, especially in summer. The persistence of the sea breeze is related to two main factors: the synoptic regional conditions (weak surface pressure gradient) and the characteristics of the land –topography–. Statistical characterization of the persistence of the sea breeze could become a useful tool in the analysis of annual and seasonal variability in atmospheric contamination levels in the Mediterranean basin.