Conveners:
Mike Hickey (Michael.Hickey@erau.edu),
Steve Smith (smsm@bu.edu),
Mike Taylor (mtaylor@cc.usu.edu)
2004 Monday 28 June 0400-0600 PM
This two-hour workshop scheduled for Monday afternoon (June 28th, 4 - 6 pm), had a short presentation/discussion format and was attended by approximately eighty people. It was convened by Mike Hickey (Embry-Riddle Aeronautical University), Steve Smith (Boston University) and Mike Taylor (Utah State University). The session was essentially divided into two sub-sessions.
The first sub-session was chaired by Mike Hickey and discussed the potential role of imaging riometers as a useful tool to measure gravity waves in the upper mesosphere through D-region absorption of cosmic radio noise. It was stressed that this approach would be useful because it would allow imaging measurements of the waves to be made during daylight hours and with overcast skies, which the airglow imagers cannot do. A recent paper on that subject was discussed, and some initial results obtained from a numerical model were presented. Questions and discussions ensued, and overall the ideas appeared to be positively received by those present. The next step is to increase the complexity of the modeling to better understand the interaction between gravity waves and the radio absorption in the D-region and to quantify what the limitations of this approach might be.
The second sub-session was devoted to mesospheric bores and was chaired by Steve Smith. Mesospheric bores have only recently been identified and so there are many questions as to their identification, their origin, and their modes of propagation. The presentation topics varied from interpretations of all-sky imager observations, the latest modelling results, and also an alternative interpretation using ducted wave modes.
Another important issue that was discussed was that these relatively uncommon events have a similar appearance to other different wave types, such as ducted and large freely-propagating gravity waves, when recorded by all-sky imaging systems. Careful analysis of the vertical phase structure of the disturbance from multi-spectral imaging measurements, as well as simultaneous measurements of the local wind and temperature fields, is therefore necessary to successfully identify and characterize these events.
The workshop was a resounding success with the talks generating several lively discussions. Although it ran over time, finishing around 6:40pm, some audience members would have stayed longer had they been given the opportunity!