Mesoscale Observing Network Course The Sea Breeze Project

1
Mesoscale Observing Network CourseThe Sea Breeze
Project

• Reijo Hyvönen, FMI
• Christer Helenelund, Vaisala

2
Suggested project title

• Characteristics of sea breeze at the Finnish
  South Coast

3
Introduction

• Purpose/goal
• To clarify the sea breeze conditions on the
  Finnish South Coast using HTB data
• What is done/methodology
• Pick suitable dates to study (May 6, May 10, July
  6 and July 8, 2006)
• Collect, summarize and analyze wind data from
  masts and wind profiler for these days for two
  cross sections along the coast
• Draw conclusions from the data obtained

4
Measurement campaigns of HTB phase 1

• May 2005 testing
• August 2005 (no database, limited
  instrumentation)
• convection, nowcasting by extrapolation
• World Championships in Athletics
• November 2005
• snow/rain
• January-February 2006
• inversions
• May 2006
• sea breeze
• fog
• August 2006
• convection

5
Measurement lines
6
Idealized sea breeze circulation
7
Measurement station in conjunction with cellular
base station
Weather transmitter h 40...100 m
Station specific URL address for Internet access
Weather transmitter h 2 m
Cell phone data transfer module and power supply
8
Malmi Wind Profiler (Vaisala LAP-3000)

• Photo from Malmi airport

9
SYNOP 2006-05-06
10
Wind Profiler measurements 2006-05-06
11
Wind Profiler measurements 2006-07-28
12
Wind measurements 2006-05-06 0330UTC
13
Wind measurements 2006-05-06 1145UTC
14
Wind measurements 2006-05-06 1800UTC
15
Wind measurements 2006-05-06 2015UTC
16
Sea breeze front 2006-07-28
Reflections from insects birds (swallows,
swifts)
17
Initial comments

• Limited HTB data available -gt Too small
  statistical basis for finding common patterns
• Many days with unclear sea breeze effect
• The general weather pattern (the geostrophic wind
  and scattered cloudiness) makes very often the
  sea breeze weaker or even or non-existent
• The scattered archipelago makes the coast line
  diffuse and also the sea breeze unclear
• The scattered topography impacts also the local
  wind (tunneling effect)
• The albedo on the shore varies quite much along
  the coast
• On top of all this, there is obviously the normal
  stochastical variation in the wind
• Based on this it might be difficult to make any
  solid conclusions