Which is the best predictor of sea temperature : satellite, model or data logger values? A case study from the Maltese Islands (Central Mediterranean)

Abstract

Water temperature data loggers were deployed at six different depths along a mooring line within Maltese coastal waters. A one-year timeseries of water column temperature data recorded by the same loggers over the September 2012- September 2013 period were compared, through the computation of Pearson correlation factor values, against satellite measures of the SST and against OPA (Ocean Parallelise) model values for the equivalent water depths. Results indicate that satellite-derived SST values are a good estimate of the water column temperature throughout the entire infralittoral zone during the winter and spring seasons, when the thermocline has not yet been established, whilst the degree of convergence between the two sets of values declines sharply during the summer and autumn seasons and extended only up to a depth of 8m and 10m, respectively. OPA model water temperature values for the various column depths give similar results when confronted against data logger values. Although the absolute thickness of the surface warm layer can’t be established, one can conclude that this layer is relatively thicker in autumn than in summer.