1. High Trace Velocity (HTV) infrasonic signals Possible origin

2. Swedish-Finnish Infrasound Network

3. Locally Observed Meteor Events

4. HTV signal signature

5. HTV signal scalogram

6. Atmospheric vortices Stenflo, L.: Acoustic solitary vortices. Phys. Fluids, 30 (10), 3297, 1987.

7. 2007-06-24 Satellite weather images

8. 2007-06-24 Occurrence of HTV signals in Kiruna and Sodankylä

9. 2007-06-24 a sample from Kiruna

10. 2007-06-24 a sample from Sodankylä

11. 2007-06-24 Sodankylä-motion pictures

12. Intensity pattern on the ground

13. Intensity ellipse

14. Shape of the intensity ellipse for both samples 230x690 m 190x380 m

15. Some properties Carry a lot of acoustic energy (up to 40 W/m2*sec) Are visible on the meteorological radar

16. 2006-05-12 Kiruna infrasound and ESRANGE radar

17. 2006-05-12 ESRANGE radar

18. Similar phenomena? Certain forms of atmospheric turbulence Cold air vortex Some boundary layer phenomena? Martian dust-devils

19. Cold air vortex

20. Martian dust-devil