A Diagram of Wind Speed Versus Air-sea Temperature Difference to Understand the Marine atmospheric Boundary Layer

This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in a series of observational studies from the early 1940s of gull flight patterns, and it was revisited in later decades to illustrate the dynamic and thermodynamic controls of fog formation, mesoscale convective clouds, surface fluxes of heat and momentum, whitecap formation, and vessel icing. The present report uses the figure to compare recent met-ocean conditions for a series of Norwegian offshore production platforms in northern Europe.