Sea surface temperatures
Sea water T varies with position in oceans
Amount of insolation absorbed depends upon angle of incidence
- With normal incidence, 98% of insolation enters water & 2% is reflected
- With oblique incidence, more light is reflected
- Warming concentrated at low latitudes
Light penetrates no more than 500 m, so therefore only warms surface waters
Have surface zone (<500 m thick) of warm water (T>18°C) & deep zone, the lower reaches of the oceans, where water temperatures are low (<3°C)