Enhanced sporadic &amp;lt;i&amp;gt;E&amp;lt;/i&amp;gt; occurrence rates during the Geminid meteor showers 2006–2010

C. Jacobi,J. Wickert,C. Arras

doi:10.5194/ars-11-313-2013

Abstract

Abstract. Northern Hemisphere midlatitude sporadic E (Es) layer occurrence rates derived from FORMOSAT-3/COSMIC GPS radio occultation (RO) measurements during the Geminid meteor showers 2006–2010 are compared with meteor rates obtained with the Collm (51.3° N, 13.0° E) VHF meteor radar. In most years, Es rates increase after the shower, with a short delay of few days. This indicates a possible link between meteor influx and the production of metallic ions that may form Es. There is an indication that the increase propagates downward, probably partly caused by tidal wind shear. However, the correlation between Es rates and meteor flux varies from year to year. A strong correlation is found especially in 2009, while in 2010 Es rates even decrease during the shower. This indicates that additional processes significantly influence Es occurrence also during meteor showers. A possible effect of the semidiurnal tide is found. During years with weaker tidal wind shear, the correlation between Es and meteor rates is even weaker.

Highlights

Sporadic E (Es) layers are thin vertical regions of enhanced electron density in the lower ionosphere
Northern Hemisphere midlatitude sporadic E (Es) layer occurrence rates derived from FORMOSAT3/COSMIC GPS radio occultation (RO) measurements during the Geminid meteor showers 2006–2010 are compared with meteor rates obtained with the Collm (51.3◦ N, 13.0◦ E) VHF meteor radar
In this paper we present Es occurrence rates detected by the GPS (Global Positioning System) radio occultation method using F3C (FORMOSAT-3/COSMIC, FORMOsa SATellite mission-3/Constellation Observing System for Meteorology, Ionosphere and Climate) data during the Geminid meteor showers 2006–2010, and compare these with meteor rates observed with VHF meteor radar

Summary

Introduction

Sporadic E (Es) layers are thin vertical regions of enhanced electron density in the lower ionosphere Their origin is generally accepted to be vertical ion drift convergence driven by vertical shears in the horizontal tidal winds, with the longliving ions needed for the layers to be provided by meteors (Whitehead, 1960). One reason may be that meteor radars, which are usually utilised to provide meteor rate seasonal cycles, only detect part of the incoming meteor flux Another possible reason is that metallic ions are relatively long-lived and some details of short-term variability are not visible in Es. Another possible reason is that metallic ions are relatively long-lived and some details of short-term variability are not visible in Es It is of interest whether shortperiod meteor events, especially meteor showers, may influence Es rates

Results

Discussion

Conclusion