Abstract
The growth of the marine internal boundary layer (MIBL, height ℎ𝑖 ) with
the shore-normal distance 𝑥, is a topic of continuing interest because
of its applications in coastal dispersion, offshore wind farm siting,
coastal air-sea fluxes and in evaporative ducting. Available data on
MIBL are only scarce, given the difficulty to measurements and
variability of coastal winds. During Coupled Air-Sea Processes and
Electromagnetic Research (CASPER)-West campaign, from September 27 to
October 27, 2017, an array of instrumentation was deployed on the
Californian coast at Point-Mugu and on the research vessel Sally Ride. A
state-of-art triple Doppler Lidar system was used to map the flow field
up to 500 m in height above sea level and to a distance of
~ 4 kilometers from the coast with a spatial resolution
of 30 m. Triple Doppler Lidar provides simultaneous vertical profiles of
all three velocity components in the atmospheric boundary layer. A 20 m
flux tower was used to characterize the atmospheric surface layer,
especially its stability. The temporal variability of MIBL growth
measured by the triple Doppler Lidar near the coast every 15 minutes
were synthesized by its offshore wind direction and atmospheric
stability. Over 5 unique case-studies of MIBL offshore development
provided some useful general conclusions on the MIBL growth.
Measurements also from a state-of-art motion-stabilized coherent Doppler
Lidar and microwave radiometer on Sally Ride also showed the growth of
offshore internal boundary layer several kilometers from the coast.