Bridge Design Project Keely Johnson Tyler Bewley Engineering B4.
Cloud Evolution and the Sea Breeze Front Jennifer Bewley Dept. of Marine and Environmental Systems...
-
Upload
berniece-boone -
Category
Documents
-
view
236 -
download
1
Transcript of Cloud Evolution and the Sea Breeze Front Jennifer Bewley Dept. of Marine and Environmental Systems...
Cloud Evolution and the Sea Cloud Evolution and the Sea Breeze FrontBreeze Front
Jennifer Bewley
Dept. of Marine and Environmental Systems
Florida Institute of Technology
Melbourne, FL 32901
OverviewOverview
• What is a sea breeze?• What is a sea breeze front?• Satellite Cloud Edge• Radar Thin Line• Why study sea breezes?• Objectives• Method• Data• Synoptic Setting• Results• Conclusions• Questions
Background InformationBackground Information• What is a sea breeze (SB)?
– Differential heating between land and sea– Formation of a thermal low over the land and a
thermal high over the water– A pressure gradient forms, air flows from high to low
pressure– Creates the sea breeze– Opposite effect happens at night creating the land
breeze
• What is a sea breeze front (SBF)?– The leading edge of the sea breeze– A drop in temperature, a wind shift, and an increase in
relative humidity occurs behind the front
Sea Breeze CirculationSea Breeze Circulation
Source: <http://www.bom.gov.au/weather/nsw/amfs/Sea%20Breeze.shtml>
Background Info. Continued…Background Info. Continued…
• Satellite Cloud Edge– Seen on visible or
infrared satellite images
– A line of cumulus clouds, parallel to the shore, with no more clouds on the seaward side of the line of development
Background Info. Continued…Background Info. Continued…
• Radar Thin Line– A region of enhanced radar reflectivity in the optically clear
boundary layer detected by a sensitive Doppler radar – Intense mixing of land and marine air provides several
interfaces capable of reflecting radio energy
Why Study Sea Breezes?Why Study Sea Breezes?
• Forecasting– Changes temperature, wind speed and direction, and
relative humidity
• Convection, Clouds, Turbulence• Climate Modeling
– Formation of clouds
• Renewable Energy– Wind and solar energy
• Operationally, how can you accurately locate the SBF?
ObjectivesObjectives
• To compare the location of the satellite cloud edge to the surface sea breeze front and the location of the radar thin line
• To analyze the differences in the location of the indicated features and create a possible vertical profile of the sea breeze front
MethodMethod• Team Beach
– Melbourne Beach– Measured air
temperature, RH, and wind speed every 15 mins.
– Sky observations, water temperature, wave height and period, salinity, and dissolved oxygen were taken every 30 mins.
• Team FIT – Collected data
Method Continued…Method Continued…
• Team Mobile Unit– Traveled west on 192, attempting to transect the SBF– The mobile unit was equipped with a wind vane, cup
anemometer, and radiometer.– Wind speeds, RH, air temperature, sky observations,
percent cloud cover and wind direction were recorded.
Method Continued…Method Continued…
DataData
• Team Beach & Team Mobile Unit– Wind speed and direction
• Team FIT– GOES 4 km visible satellite
imagery – Melbourne NWS Doppler
radar base reflectivity images
– Other surface observations
Synoptic SettingSynoptic Setting
Synoptic SettingSynoptic Setting
Synoptic SettingSynoptic Setting
ResultsResults
• Analyzed the progression of the cloud edge, thin line, and the surface fronts
• Developed a model to find the relation of the features for each day
Results Continued…Results Continued…
Location
Time Distance
Date Radar Cloud Edge Radar Cloud EdgeMay 25* N/A 25 mins behind
surface front
N/A 6.9 km behind
surface front
May 26 N/A 75 mins behind
surface front
N/A 8.1 km behind
surface front
May 27 50 mins ahead
surface front
10 mins behind
surface front
1.5 km ahead
surface front
1.7 km behind
surface front
May 25* = Strong easterly flow
May 25May 25
May 26May 26
May 27May 27
ConclusionsConclusions
• The thin line precedes the surface front which precedes the cloud edge
• The actual distances between these features vary and depend on several factors – Operationally, the satellite cloud edge may not always
be a good indication of the location of the surface SBF
• One improvement would be to have higher resolution data, especially satellite and radar imagery and more sampling sites
AcknowledgementsAcknowledgements• A special thanks to…
– Mr. Splitt for advising this project and aiding with the creation of figures
– Mr. Leslie for the mobile renewable energy station
– Andrew Condon for the synoptic maps
– All the MFP students and TA’s for helping with the data collection
Questions?Questions?
Brian ZachryBrian Zachry