SST: 6-day composite SST (L3S-6d, QL≥2) using night-only SST in a 6-day window centred on t0, the analysis time. The 6-day window is used to maximise coverage and night-only SST is used to minimise bias due to diurnal heating. The 6d composites are produced by the BoM for IMOS using GHRSST protocol on a 2x2km grid. All SST is adjusted by the SSES bias before compositing and an offset of 0.17C is added to obtain the bulk SST.
SST Anomaly: The SSTAARS climatology, calculated for each 2x2km pixel for the analysis date, t0, is removed from the SST.
Percentiles: The SST anomalies are ranked against almost 25 years of anomalies (1992-2016). The percentiles have been evaluated at each pixel for every day of the year. Anomalies falling in the <10 rank (dark blue) are the coldest 10% of observed anomalies at that pixel for that day of the year. Similarly, anomalies ranked >90 are the hottest 10% of observed anomalies. Green percentiles (two shades) represent the average 20% of temperature anomalies.