Winds in the strait of gibraltar

Automated meteorological observations were made from October 1985 to September 1986 in the narrows of the Strait of Gibraltar. Additional surface and upper‐air measurements were made in the Strait from May to July 1986. the main wind events in summer were mostly mesoscale levanters (winds from the east through the Strait), and a lesser number of synoptic‐scale levanters and westerlies. During mesoscale levanters, the wind speed increased and the pressure decreased from Gibraltar downstream through the narrows as far as Tangier. A mesoscale low and the highest winds were found over the axis of the Strait, north of Tangier. High‐velocity (20 m s−1) winds occurred only under 1 ‐km height. the air‐temperature profile became progressively warmer moving from Gibraltar towards Tangier. A weak air‐temperature inversion decreased in height to the west of the narrows. Venturi flow as an explanation for the downstream increase of the low‐level winds during a levanter is inconsistent with observations. A new model is proposed to explain the wind field associated with levanter winds in the Strait that includes some orographic blocking and low‐level convergence into the narrows, some west‐side divergence due to drag over water, and leeside heating that generates a leeside, mesoscale low pressure. the surface low accelerates the surface winds to their maximum strength well downstream of the narrows. A similar flow regime has been observed recently in the sea‐level channel between Hawaii and Maui.