Sea/land-breeze events on the Monterey Bay are examined using data from the 915-MHz wind profiler and RASS systems. These sensors were deployed during Jun-Aug 1994 in conjunction with the REINAS Project conducted by various scientific institutions in the region. Data analyzed are continuous radar and virtual temperature returns located at four sites strategically positioned around the bay. This relatively new remote sensing device provides information on maximum and minimum sea/land breeze heights, onset and cessation times, virtual temperature distribution with height, and the effect of mountainous coastal topography on the sea and land breeze system.
The sea breeze circulation was investigated using a combination of acoustic doppler sodar, doppler lidar and conventional observations in central California on the coast of Monterey Bay. The study was called LASBEX (Land Sea Breeze EXperiment). A monostatic three-axis phased-array doppler sodar was able to detect the various features of the sea breeze front, which has many of the characteristics of a gravity head current produced in laboratory experiments, such as the longitudinal vortex, lobe and cleft structure, and strong regions of turbulence and convergence. Profiles of the wind field and its component variances were generated every five minutes. Vertical velocities up to 1.0 m/s were detected in the updraft region at the front. Vertical velocity fields were used to derive the horizontal divergence associated with the sea breeze and values of convergence in the range of .004/s and greater were calculated. These are believed to be more accurate values than any found in previous sea breeze studies. Doppler lidar radial velocity information was useful in mapping the various layers and wind structure of the sea breeze. The wind field of the sea breeze by the lidar was compared with the sodar. The results of this comparison showed that the sodar was well suited to investigate features under 600 meters in height, such as the updraft region behind the front and the variance of the wind, whereas the lidar was better at describing the larger scale flow, such as the return flow of the sea breeze, the convergence zone along the sea breeze front and prevailing synoptic winds. Together, these instruments gave a comprehensive and complete description of the sea breeze frontal structure, evolution and movement. Theses.(jhd).
Sea breeze events on the Monterey Bay are examined from a single station at the mouth of the Salinas Valley. Data analyzed are continuous, two- minute meteorological samples of windspeed, wind direction, temperature, dew point, incoming shortwave irradiance, and incoming longwave irradiance. A speed index is defined using the average hourly maximum and minimum windspeeds oriented in the cross-shore direction thereby reflecting the thermally induced diurnal windspeed enhancement. Large-scale effects on this mesoscale circulation are presented through evaluation of changes in boundary layer depth with changes in speed index. Changes in boundary layer depth as reflected in trends of inland stratus penetration and offshore flow provide insight for anticipating sea breeze intensity.
On 25 August a controlled burn on the former Fort Ord property raged out of control. The sea breeze was responsible for transporting the acrid smoke into the Salinas Valley. The PSUINCAR mesoscale model, MMS, was run at 4 km grid resolution twice using two different PBL schemes (MRF and Burk-Thompson) and then verified by observations from several local mesoscale networks, including wind profiler data. The MM5 simulation was able to depict the 3-D structure of the sea breeze and differentiate between the local mountain- valley forcing and the large-scale sea breeze forcing. These two individual forcing mechanisms were responsible for an observed double surge in the time series of winds at Fort Ord. Further investigation is needed into the surface parameterization/land use tables to improve the surface forcing.
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