Marine boundary layer

The marine boundary layer is the lowest part of the atmosphere over the ocean and responds directly to the ocean surface through turbulent exchange of heat, moisture, and momentum.

Main controls

Its structure depends strongly on sea surface temperature, near-surface winds, surface fluxes, and the strength of the overlying inversion. Over cool water, the marine boundary layer is often shallow and stable. Over warmer water, it tends to deepen and couple more effectively to convective processes aloft.

Why it matters

Its depth and stability control whether low clouds, fog, and drizzle can form. Over cool water, the marine boundary layer is often shallow and stable, favoring Stratocumulus and a strong temperature inversion. Over warmer water, it tends to deepen and support stronger convective mixing.

In the Galapagos

The Galapagos Cold Pool cools the lower atmosphere and helps maintain a shallow marine boundary layer during the Garua season. That structure traps moisture below the inversion and supports the low-cloud regime that shapes highland Occult precipitation.

Why it matters for modeling

Accurately representing the marine boundary layer is critical for simulating low-cloud cover, drizzle, inversion strength, and air-sea exchange. In the Galapagos, those are exactly the processes that determine whether a model reproduces garua conditions or shifts too easily into convective rainfall.

See also: Sea surface temperature, Temperature inversion, Stratocumulus, Garua, WRF