1. Mesoscale Observing Network Course The Sea Breeze Project Reijo Hyvönen, FMI Christer Helenelund, Vaisala

2. ©Vaisala | CH | December 2006 | Page 2 Suggested project title Characteristics of sea breeze at the Finnish South Coast

3. ©Vaisala | CH | December 2006 | Page 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. ©Vaisala | CH | December 2006 | Page 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. ©Vaisala | CH | December 2006 | Page 5 Measurement lines

6. ©Vaisala | CH | December 2006 | Page 6 Idealized sea breeze circulation

7. ©Vaisala | CH | December 2006 | Page 7 Measurement station in conjunction with cellular base station Weather transmitter h = 40...100 m Weather transmitter h = 2 m Cell phone data transfer module and power supply Station specific URL address for Internet access

8. ©Vaisala | CH | December 2006 | Page 8 Malmi Wind Profiler (Vaisala LAP-3000) Photo from Malmi airport

9. ©Vaisala | CH | December 2006 | Page 9 SYNOP 2006-05-06

10. ©Vaisala | CH | December 2006 | Page 10 Wind Profiler measurements 2006-05-06

11. ©Vaisala | CH | December 2006 | Page 11 Wind Profiler measurements 2006-07-28

12. ©Vaisala | CH | December 2006 | Page 12 Wind measurements 2006-05-06 03:30UTC

13. ©Vaisala | CH | December 2006 | Page 13 Wind measurements 2006-05-06 11:45UTC

14. ©Vaisala | CH | December 2006 | Page 14 Wind measurements 2006-05-06 18:00UTC

15. ©Vaisala | CH | December 2006 | Page 15 Wind measurements 2006-05-06 20:15UTC

16. ©Vaisala | CH | December 2006 | Page 16 Sea breeze front 2006-07-28 Reflections from insects & birds (swallows, swifts)

17. ©Vaisala | CH | December 2006 | Page 17 Initial comments Limited HTB data available -> 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