The regional warming trend: vertical profiles of summer temperatures (June-August) in the western Arabian Sea averaged over decades along Omani coast.
The decadal vertical profiles shown in this figure are based on a substantial amount of historical data. For example, the number of profiles averaged for the “oldest” time range (1960-1970) was 790, for the 1971-1980 time range, 972 were available; for the 1981-1990 range it was 1277, for the 1991-2000 time range - 1205, and for the 2001-2010 range it was 482.
Maximal increase of temperature measured as the difference between the “oldest” mean vertical profile (1960-1970) and the newest one (2000-2010) was 2.3 ± 0.9oC in the upper mixed layer. The mean regional warming we report here for the past 50 years has exceeded the global warming trend values (Piontkovski and Chiffings, 2014).
The interannual sequence of averaged vertical profiles exhibits the strengthening of the vertical stratification of the water column over years; the phenomenon that might have negative ecological consequences underlying the decline of biological productivity in the region (Piontkovski et al., 2013).