Geminids seen by Dynasonde
Although it is cloudy in Tromsø so that we cannot see the Geminid meteor shower, we can see the effects of the meteors as they burn up and ionize the upper atmosphere, in the HF echoes from an ionosonde (of type Dynasonde) at EISCAT's site in Ramfjordmoen. The plots below show lots of short-lived echoes in the E region, at around 100 km height which appeared slowly on 12 December, and seem to peak this morning on 14th December. The plasma frequencies are in the 1-4 MHz range. The daytime echoes above 200km are from the normal F region, produced by solar ionization of the atmosphere, and the other sporadic echoes are mostly from auroral particle precipitation. More plots with more details can be found here, with updates to these 24-hr plots labelled DSND.
