The Impact of Synoptic-Scale Flow on Sea Breeze Front Propagation and Intensity at Eglin Air Force Base
The Impact of Synoptic-Scale Flow on Sea Breeze Front Propagation and Intensity at Eglin Air Force Base

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Published: 2006

Total Pages: 109

ISBN-13:

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This study investigates the impact of the synoptic-scale flow on the propagation and intensity of the sea breeze front at Eglin Air Force Base. The 925 mb wind direction and speed from the 12 UTC Tallahassee sounding was used to categorize 509 summer days as having an offshore, onshore, or coast parallel synoptic-scale flow regimes. Days with similar synoptic-scale flows were then composite together to create hourly surface analyses for each regime. Sea breeze frontogenesis, location and intensity were analyzed on hourly plots of temperature, winds and frontogenesis. Results indicate that the most intense sea breeze fronts formed under 3-5 ms (exp -1) offshore, 7-9 ms (exp -1) coast parallel easterly, and 3-5 ms (exp -1) coast parallel westerly synoptic-scale flow while the weakest fronts formed under 0-3 ms(exp -1) onshore and coast parallel westerly flow. The inland penetration of the sea breeze front was restricted under offshore flow but propagated through the Elgin Range Complex under onshore flow. The intensity of the sea breeze front was found to be a balance between convergence (frontogenetic) and turbulent mixing (frontolytic). Under onshore flow the sea breeze front formed late in the afternoon when convergence at the front was maximized and turbulent mixing decreased. Under offshore flow, the strongest sea breeze fronts formed early in the afternoon due to strong convergence between offshore and onshore winds and weak turbulent mixing.

The Sea Breeze Circulation During the Land Sea Breeze Experiment (LASBEX) in Central California
The Sea Breeze Circulation During the Land Sea Breeze Experiment (LASBEX) in Central California

Author: Michael Fagan

Publisher:

Published: 1988

Total Pages: 139

ISBN-13:

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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).

Influence of Earth Surface and Cloud Properties on the South Florida Sea Breeze
Influence of Earth Surface and Cloud Properties on the South Florida Sea Breeze

Author: Patrick T. Gannon

Publisher:

Published: 1978

Total Pages: 100

ISBN-13:

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A two-dimensional numerical sea breeze model that includes radiation and heat budget physics is used to study sea breeze circulations affected by South Florida surface and cloud conditions. Sensitivity experiments show major differences in the intensities and inland penetrations that result from prescribed distributions of surface and cirrus cloud properties. A case study experiment for July 16, 1975, provides a measure of the importance of surface and cumulus cloud properties that were observed or deduced for this one day. Significant differences exist between the model version using a surface heat budget formulation and the version using prescribed thermal forcing. The strength of the sea breeze predicted with the heat budget formulation decreases with increasing initial basic state wind speeds, while the opposite effect occurs with thermal forcing. Soil moisture is the dominant controlling surface property, followed by albedo and thermal inertia. Cirrus clouds can prevent the evolution of the sea breeze when the geometric thickness of cirrus exceeds 2 km. A case study demonstrates the importance of cumulus cloud shielding of the surface from solar radiation. The mesoscale sea breeze convergence zone is seen to evolve adjacent to organized cloud fields, but not necessarily coincident with them. This is an important consideration when sea breeze models are verified with observed cloud fields.

The Sea Breeze as a Function of the Prevailing Synoptic Situation
The Sea Breeze as a Function of the Prevailing Synoptic Situation

Author: Mariano A. Estoque

Publisher:

Published: 1961

Total Pages: 20

ISBN-13:

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The effects of the large-scale wind and temperature fields on the development of the sea breeze circulation was studied with the aid of a theoretical model. The model, which applies to a straight coastline, was integrated numerically to obtain time and space variations of the wind and temperature fields. The results of several integrations using different geostrophically balanced initial conditions are presented. (Author).

Transient Ship Synoptic Reports
Transient Ship Synoptic Reports

Author: Joseph Austin Schrock

Publisher:

Published: 1976

Total Pages: 308

ISBN-13:

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Coastal fog studies have always alluded to offshore marine fog development by extending known observations along the coast seaward. This velocity study attempts to establish the offshore conditions during one such coastal fog study through the analysis of transient ship synoptic reports. Over 1400 ship reports occurring off the coasts of California, Oregon, and Washington during two weeks in August 1974 and one week in December 1975 were analyzed. The visibility-weather group elements of the ship reports along with daily NOAA II satellite photographs were used to establish fog location and boundaries. Other Synoptic parameters such as air temperature, pressure patterns and sea surface temperature were studied in an attempt to determine reasons for marine fog development. An evaluation of the credibility and reliability of transient ship synoptic reports also was made.