Upper atmosphere potassium layer and its seasonal variations at 54°N

Sporadic Ca and Ca<sup>+</sup> layers at mid-latitudes: Simultaneous observations and implications for their formation

“…In spite of this, the Ca s rate at Kühlungsborn, Germany was found to be 43% in annual mean. Also for the site of Kühlungsborn, Eska et al (1998) report on 16 nights with strong K s out of 110, thus roughly a rate of 15% on a nightly basis. Even this limited set of mid-latitude sporadic layer statistics give a Ca s rate that is at least by a factor of 1.5 higher than observed for other metals.…”

Longitudinal variability of mesospheric temperatures during equinox at middle and high latitudes

“…The K-lidar absolute accuracy is of the order of 2 K. The observed temperature di erence at 87 km height was estimated to be about 2 K, and thus well within the combined error of (less than) 4 K. The transportable K-lidar was built by the Leibnitz Institute of Atmospheric Physics (IAP) and operates at 770 nm wavelength probing a Doppler broadened potassium line in the atmosphere to determine vertical potassium density and temperature proÿles at 80-105 km height, covering the mesopause region (i.e. Fricke-Begemann et al, 1998Eska et al, 1998). The method for deriving densities and temperatures from the K-lidar observations has been described by von von Zahn and H o ner (1996).…”

Modeling of the Atmospheric Response to the Leonid Meteor Showers

“…Also shown in Figure 1 is the curve after it has been adjusted to give a K column density of 2.5(7) cm" 2 , which is the result of Eska, et al [1998] for the same region in November. The dust influx is given a diurnal variation according to the diurnal variation in the number of sporadic meteors as measured by radar.…”

“…The background model, which was originally made for sodium, is given revised chemistry and is evaluated at the Kuhlungsbom site at the appropriate time. The total influx of background cosmic dust is adjusted to match the climatology recently measured at the site for potassium by Eska, et al [1998]. In order to apply this to the Leonid meteor shower, a second mass distribution must be derived, which we do from visual meteor data presented by Arlt et al [1997].…”