Nearshore sea temperature variability off Rottnest Island (Western Australia) derived from satellite data
Taylor and Francis
School of Natural Sciences
While satellite‐derived sea‐surface temperatures (SSTs) have been widely used in open ocean monitoring, they have rarely been applied to the nearshore region. In this study, full‐resolution Advanced Very High Resolution Radiometer (AVHRR) satellite data were used to derive a sea temperature climatology for three nearshore sites at Rottnest Island (Western Australia) for the 7‐year period 1995 to 2001. Because of the proximity to the land, image geolocation and careful pixel selection were crucial. The mean annual cycle shows the influence of both air–sea heat flux in the shallow waters and the seasonal strengthening of the tropical Leeuwin Current. Self‐recording temperature loggers were installed on near‐surface buoys for a few months in 2001 to assess how reliably the satellite temperatures could be used in such a dynamic nearshore environment. About 80% of the individual satellite temperatures were within ±0.5°C of the logger measurements (at the same time of day) and over 95% were within ±1°C. Occasionally, however, the satellite temperatures differed from the in situ measurements by more than 2°C and possible reasons for this are discussed. The monthly mean satellite temperatures were generally within 0.3°C of the monthly logger averages, which may be taken as a practical reliability limit for the climatology.