Observations of the stratospheric conductivity and its variation at three latitudes

Abstract

Measurements of the atmospheric conductivity from nine high‐altitude balloon flights are presented. The measurements were obtained between the altitudes of 10 and 30 km at three locations widely separated in latitude, providing the opportunity to investigate conductivity variations on local and global scales. The data contribute to the set of global conductivity measurements, which are generally lacking. The conductivity profiles exhibit a considerable variability from day to day which does not correlate with solar or cosmic ray activity. The variations are apparently dominated by local effects. The conductivity measurements provide evidence of stratospheric aerosol layers with number densities of the order of 1000 cm−3. The observed variation of the conductivity with latitude is much larger than that predicted by a latitudinal variation of cosmic ray ionization alone. A global background distribution of aerosols is estimated and parameterized. By including the effects of aerosols and latitudinal temperature variations, the agreement between the predicted variation of conductivity with latitude and the observed variation is significantly improved. The implication is that present global models of the conductivity, which employ latitudinal variations based on cosmic ray ionization alone, may be improved by including the effects of latitudinal variations of temperature and aerosols. The effects of photoelectric emissions on relaxation time conductivity measurements are discussed.

Measurements of Atmospheric Electricity Aloft

“…Changes in conductivity due to aerosol layers in the stratosphere have been observed by Kondo et al (1982a;1982b); Rosen et al (1985); and Byrne et al (1988) mainly from balloon platforms. Gringel and Muhleisen (1978) measured the number concentration of small particles and conductivity simultaneously from a balloon platform, in which conductivity was found to decrease by ≈11% in a layer in which the particle number concentration was 2000cm -3 above the background value.…”

“…Vertical profiles of conductivity have been measured by this method by many investigators including Kellogg and Weed (1968); Hale et al (1968); Mozer and Serlin (1969); Mitchell and Hale (1973); Byrne et al (1988); Hu and Holzworth (1996); Holzworth and Bering (1998) ;Bering et al (2005) and John et al (2009) using free balloons, constant altitude balloons and rockets. The relaxation method is also popular on space missions, as the same probe instrument can be used to determine both conductivity and electric field, thus saving space and power, which is in small supply e.g.…”

“…Nearer the geomagnetic poles, the energy barrier to incoming particles reduces, therefore at the poles, the full energy spectrum of GCRs can penetrate the atmosphere. The latitudinal variation of conductivity has been investigated by several researchers using high altitude balloons (Byrne et al 1988;Hu and Holzworth 1996) and aircraft (Markson 1985;Driscoll et al 1996). Driscoll et al (1996) measured the latitudinal distribution of conductivity in the stratosphere using the high altitude ER-2 aircraft.…”

Latitude gradients in the natural variance in stratospheric conductivity – Implications for studies of long-term changes

“…Thus this technique is useful only for altitudes above 10 km. An extensive discussion of the expected response of the probes and the methods used to obtain the conductivity data can be found in Byrne et al (1988Byrne et al ( , 1990Byrne et al ( , 1991.…”

“…In previous publications (Byrne et al, 1988(Byrne et al, , 1991Bering et al, 2003), we investigated these and other effects extensively with regard to their effects on our conductivity data from the earlier flights (prior to 1987). In our most recent survey paper, it was suggested that there may be a latitude gradient in the natural variance of stratospheric conductivity (Bering et al, 2003).…”