Whistler waves caused by lightning are known to penetrate the ionosphere with significant wave amplitudes. Recent rocket experiments have shown that lightning from sources as far as 1000 km from the ionospheric rocket subtrack are easily seen. The spectral energy density of lightning in the ionosphere often has significant power at frequencies near and below 1 kHz. Such low‐frequency whistler waves can propagate all the way to the magnetopause boundary layer if they begin in the cusp or polar cap. Lightning is common over high‐latitude continental land masses in the summer months which places this wave source function well within range of the cusp and polar cap. Ray tracing studies using a global three‐dimensional two‐fluid code are conducted to investigate the propagation of these whistler waves into the high latitude magnetosphere. The estimated, mapped lightning whistler wave amplitude is compared to wave intensity measurements from ISEE and AMPTE and supports the argument that falling tone whistler waves, seen by Geotail near the dayside magnetopause, may have been from intense lightning. It is found that the mapped whistler wave amplitude from lightning is comparable to the in situ wave amplitudes measured in the outer dayside magnetosphere and low latitude boundary layer.

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[1] Transient luminous events above thunderstorms such as sprites, halos, and elves require large electric fields in the lower ionosphere. Yet very few in situ measurements in this region have been successfully accomplished, since it is typically too low in altitude for rockets and satellites and too high for balloons. In this article, we present some rare examples of lightning-driven electric field changes obtained at 75-130 km altitude during a sounding rocket flight from Wallops Island, Virginia, in 1995. We summarize these electric field changes and present a few detailed case studies. Our measurements are compared directly to a 2D numerical model of lightning-driven electromagnetic fields in the middle and upper atmosphere. We find that the in situ electric field changes are smaller than predicted by the model, and the amplitudes of these fields are insufficient for elve production when extrapolated to a 100 kA peak current stroke. This disagreement could be due to lightning-induced ionospheric conductivity enhancement, or it might be evidence of flaws in the electromagnetic pulse mechanism for elves.

Every electric field instrument flown on sounding rockets over a thunderstorm has detected pulses of electric fields parallel to the Earth's magnetic field associated with every strike. This paper describes the ionospheric signatures found during a flight from Wallops Island, Virginia, on 2 September 1995. The electric field results in a drifting Maxwellian corresponding to energies up to 1 eV. The distribution function relaxes because of elastic and inelastic collisions, resulting in electron heating up to 4000–5000 K and potentially observable red line emissions and enhanced ISR electron temperatures. The field strength scales with the current in cloud‐to‐ground strikes and falls off as r−1 with distance. Pulses of both polarities are found, although most electric fields are downward, parallel to the magnetic field. The pulse may be the reaction of ambient plasma to a current pulse carried at the whistler packet's highest group velocity. The charge source required to produce the electric field is very likely electrons of a few keV traveling at the packet velocity. We conjecture that the current source is the divergence of the current flowing at mesospheric heights, the phenomenon called an elve. The whistler packet's effective radiated power is as high as 25 mW at ionospheric heights, comparable to some ionospheric heater transmissions. Comparing the Poynting flux at the base of the ionosphere with flux an equal distance away along the ground, some 30 db are lost in the mesosphere. Another 10 db are lost in the transition from free space to the whistler mode.

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