Pressure changes

Pressure changes
Pressure changes Several pressure loggers (barometers 50,52, 53), as well as a microbarometer (a sensitive pressure sensor that indicates pressure changes rather than the absolute value) show a distinct pair of vortex passage events that can be matched to events seen in the seismic tilt (N/S and E/W acceleration). The wind speed and direction was only measured once a minute so does not pick up these short events. Note that time axis is in 100 second units. High pass filtering of the vertical axis of the seismometer also shows noise that correlates with the vortex passage. Some of this may be due to wind loads on the fence or equipment boxes. Sharon Kedar