MEASUREMENTS OF TEMPERATURE-FLUCTUATIONS IN BREAKING SURFACE-WAVES

Measurements of temperature fluctuations and air entrainment within th e upper 1 m of the surface caused by breaking surface waves have been acquired with a novel surface-following sensor array. Brief temperatur e fluctuations of order 20 mK-100 mK lasting up to 1.5 s and coinciden t with wave breaking are observed. Although a few of the temperature f luctuations represent direct measurements of the temperature of entrai ned air in large bubbles, it appears that in many cases the disruption of the ocean thermal boundary layer and its vertical mixing is observ ed. The observations suggest that wave breaking may play a role in the vertical mixing of warm or cool water stored in the top few centimete rs near the ocean surface to depths at which more persistent structure s continue the process. Only about 30% of whitecaps exhibit this tempe rature fluctuation. The authors hypothesize that measurable thermal in jections tend to be concentrated in Langmuir convergence zones, which accentuate the thickness of the ocean thermal boundary layer.