What do the sea temperature charts show?
The sea temperature charts show sea surface temperature anomalies for both the Australian region and the entire world. That is, it shows how far above or below average the sea surface temperatures are at any location.
Areas of above average sea surface temperatures generally favour increased evaporation and hence higher rainfall, if a trigger is in place. Areas of below average sea surface temperatures are generally associated with lower than normal rainfall.
Sea Surface Temperature Anomalies - Global
The Sea Surface Temperature Anomaly (SSTA) map shows the difference between observed SSTs and long-term average SSTs for that time of year. The data displayed is the weekly average, centred on the date shown in the heading. Positive SSTAs (towards the red end of the spectrum) are usually correlated with increased regions of convection (conducive to cloudiness and rainfall), while negative SSTAs (at the blue end of the spectrum) are usually associated with reduced convection and clearer skies.
SSTAs can be used as an indicator of the phase of global climate fluctuations, such as the El Nino Southern Oscillation (ENSO). For example, prolonged positive SSTAs observed off the eastern coast of the South Pacific can indicate the atmosphere is experiencing an El Niņo episode.
Sea Surface Temperatures - Global
The Sea Surface Temperature (SST) map displays weekly average SSTs centred on the date shown in the heading. Surface ocean temperatures vary much slower than atmospheric temperatures due to the higher heat capacity of water (i.e. the oceans require a greater amount of energy to be heated compared with the atmosphere).
As such, SSTs generally lag atmospheric temperatures on a seasonal timescale by about 3 months. The lowest SSTs are usually observed in early Spring, and the highest in early Autumn. In tropical regions, SSTs greater than 26.5°C are considered suitable for the formation of tropical cyclones.
Sea Surface Temperatures Anomalies - Australia
The Sea Surface Temperature Anomaly (SSTA) map shows the difference between observed SSTs and long-term average SSTs in the Australian region for that time of year. The data displayed is the weekly average, centred on the date shown in the heading. Positive SSTAs (towards the red end of the spectrum) are usually correlated with increased regions of convection (conducive to cloudiness and rainfall), while negative SSTAs (at the blue end of the spectrum) are usually associated with reduced convection and clearer skies.
SSTAs can be used as an indicator of the phase of regional climate fluctuations, such as the El Nino Southern Oscillation (ENSO). For example, prolonged negative SSTAs observed off the eastern coast of the South Pacific can indicate the atmosphere is experiencing an El Niņo episode, conducive to drier than average rainfall across eastern Australia.
Sea Surface Temperatures - Australia
The Sea Surface Temperature (SST) map displays weekly average SSTs in the Australian region centred on the date shown in the heading. Surface ocean temperatures vary much slower than atmospheric temperatures due to the higher heat capacity of water (i.e. the oceans require a greater amount of energy to be heated compared with the atmosphere).
As such, SSTs generally lag atmospheric temperatures on a seasonal timescale by about 3 months. The lowest SSTs are usually observed in early Spring, and the highest in early Autumn. In tropical regions, SSTs greater than 26.5°C are considered suitable for the formation of tropical cyclones.