SKiYMET Meteor Radar: Wind and Temperature

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For more information about SkiYMET Meteor Radar and data, please, contact Dr. Chris Meek.

Meteor (ionized) trails, although of short duration (<~ 1 s), are detected by the SKiYMET and their radial velocity estimated by Doppler shift. The radar only “sees” those trails when they are perpendicular to the line of sight, i.e., the trail acts as a mirror for radio waves. Trails disperse quickly, but during their lifetime, and because the background atmosphere is relatively dense, they are carried along by the wind, of which the measured line-of-sight Doppler velocity is only a component.

To measure the total wind, at least two trails are required in different directions, there are typically 300 per hour spread amongst the sampled heights, 82-97 km. The time-sequences of winds or vectors exhibit diurnal and semi-diurnal tidal oscillations as well as higher frequency gravity waves and transient planetary waves. These various waves dominate the dynamics of the atmosphere 30-100 km. Winds measured by the radar allow the nature/variability of the extension of the Polar Vortex above 55-70 km to be uniquely studied. The breakdown of the Polar Vortex modifies the chemistry and aeronomy of the atmosphere and couplings between the Arctic and the equatorial and Antarctic regions which lead to modifications in weather and climate.

The radar is currently located near the airport (SAFIRE site) at Eureka (80N, 86W). It was installed at OPAL site in 2005/2006 and started operation on Feb. 15 2006. Except for a period September 2013 to September 2015 (serious equipment failure, at which time it was moved to also minimize local noise), and some relatively short downtimes, it runs continuously. A Canadian Space Agency grant (Dynamics of the Neutral Thermosphere) during 2015-2018, which contributed to the repair and move, required that the raw data be publicly available – and this was done. But since then, that program has expired, and these data and ancillary information files are archived in Toronto, no longer public access.

Experiment Details

The antenna consist of a wide angle “all-sky” transmitter antenna and a receiving array of 5 antennas arranged in an “X” (but in our case, one had to be moved to reduce local noise pickup). Each line has two spacings: 2.5 and 2 radio wavelengths. This reduces coupling between antennas but still allows for unambiguous angle of arrival determination (because the difference in the two legs is 0.5 wavelengths, or 180 degrees in phase). Hocking et al. 2001 is the best reference for the radar.

The default sampling parameters are 82 – 97 Km (6 heights), each with a 3 Km layer and 90 minute time resolution. These can be changed in re-analyses by using raw echo data depending on their availability.