Vertical profile measurements of lower troposphere ionisation

Abstract

a b s t r a c tVertical soundings of the atmospheric ion production rate have been obtained from Geiger counters integrated with conventional meteorological radiosondes. In launches made from Reading (UK) during 2013-2014, the Regener-Pfotzer ionisation maximum was at an altitude equivalent to a pressure of (63.1 7 2.4) hPa, or, expressed in terms of the local air density, (0.1017 0.005) kg m À 3 . The measured ionisation profiles have been evaluated against the Usoskin-Kovaltsov model and, separately, surface neutron monitor data from Oulu. Model ionisation rates agree well with the observed cosmic ray ionisation below 20 km altitude. Above 10 km, the measured ionisation rates also correlate well with simultaneous neutron monitor data, although, consistently with previous work, measured variability at the ionisation maximum is greater than that found by the neutron monitor. However, in the lower atmosphere (below 5 km altitude), agreement between the measurements and simultaneous neutron monitor data is poor. For studies of transient lower atmosphere phenomena associated with cosmic ray ionisation, this indicates the need for in situ ionisation measurements and improved lower atmosphere parameterisations.

Stratiform cloud electrification: comparison of theory with multiple in‐cloud measurements

“…Nicoll and Harrison, ) or indirectly by measuring the ion production rate. Measurements showing the ion production rate variation with height have been presented by Harrison et al () using the balloon‐borne Geiger sensor described in section 3.1. In this study, measurements of vertical profiles of ionisation rate have been obtained at all three cloud measurement sites of Reading, Hyytiala and Halley, which allow the average vertical ion production rate profile from the surface up to 5 km for all of the sites together to be found, as well as the clear‐air conductivity profile (shown in Figure (a)).…”

Modes of temperature and pressure variability in midlatitude troposphere and lower stratosphere in relation to cosmic ray variations

“…On one hand, this dependence can result from the mentioned (section 1) local atmospheric effect (i.e., dependence of the ground measure CR flux on the atmospheric depth and/or pressure anomalies at the heights where secondary particles are generated) that is still present in the pressure-corrected ground-measured neutron monitor data. This possibility was discussed previously in, e.g., Aplin et al [2005], Sloan et al [2011], andHarrison et al [2014]. On the other hand, the variations of the CR measured by neutron monitors over the whole globe used to be very well correlated (contrary to the stratospheric conditions), and the observed small differences, mainly in FD amplitude and the observation of ground level enhancements, can be attributed to their R c or to the more or less favorable longitudinal position of a neutron monitor.…”

“…[], and Harrison et al . []. On the other hand, the variations of the CR measured by neutron monitors over the whole globe used to be very well correlated (contrary to the stratospheric conditions), and the observed small differences, mainly in FD amplitude and the observation of ground level enhancements, can be attributed to their R c or to the more or less favorable longitudinal position of a neutron monitor.…”

Experimental investigation of ion–ion recombination under atmospheric conditions

“…The contribution of galactic cosmic rays at mid-latitudes, as presented by Usoskin et al (2004), is shown in cyan. Black crosses indicate measurements by Harrison et al (2014). The double arrow at the top shows the range of q explored in this study.…”

“…1; Harrison and Carslaw, 2003;Kazil and Lovejoy, 2004;Usoskin et al, 2004;Arnold, 2008;Zhang et al, 2011;Williams et al, 2011;Harrison et al, 2014).…”