(Fig. 3.9). Water loss to the atmosphere and riverine inputs combined lead to an
estimated Mediterranean freshwater deficit of about 500 mm year
À1 , consistent with
most oceanographically based estimates for water flux from the Atlantic Ocean at the
Gibraltar Strait. The annual mean resulting tendency to increased salinity is balanced
by river discharge of freshwater and salt export to the Atlantic through the Strait of
Gibraltar (Mariotti et al. 2002). Over the Alboran Sea mean P–E is also negative
throughout all seasons (Fig. 3.10), being the annual mean values (in the 1979–2014
period) for P, E and P–E, obtained from ERA-Interim (Dee et al. 2011) along 36
N,
531 mm year
À1 , 1051 mm year
À1 , and À520 mm year
À1 , respectively.
Precipitation variability presents a strong seasonal cycle modulated by interannual to multidecadal variability patterns. The annual variation coefficient is very
high in the western Alboran, with values over 30% in the Strait of Gibraltar. There
Fig. 3.6 Box and whiskers diagrams for monthly precipitation (mm) recorded in Málaga, Almería,
and Melilla stations. The minimum and maximum values are denoted with a horizontal dash in the
upper and lower limits of whiskers, the edges of the boxes of box correspond to 10th, 25th, 75th,
and 90th percentiles of the data distributions, and the central bold reddish and blue bars denote the
median and the mean, respectively. Source: AEMET
3 Alboran Sea Area Climate and Weather
37