ELF sferic energy as a proxy indicator for sprite occurrence
نویسندگان
چکیده
Broadband ELF/VLF measurements of sferics near Ft. Collins, Colorado, demonstrate that ELF sferic energy is a proxy for sprite occurrence which can be used to estimate the number of sprites produced by a thunderstorm. Ultra-long range (∼12,000 km) measurements at Palmer Station, Antarctica, confirm the application of this proxy to storms where no video observations of sprites are available. Comparison with high-resolution photometer measurements demonstrate the simultaneity of sprite luminosity and an ELF “second pulse” believed to be radiated by electrical currents within the sprite body [Cummer et al., 1998]. Measurements of the second ELF pulse are used to identify a quantitative relationship between the current in sprites and total sprite luminosity.
منابع مشابه
Modeling ELF radio atmospheric propagation and extracting lightning currents from ELF observations
Observations of extremely low frequency (ELF) radio atmospherics (sferics), the transient electromagnetic fields radiated by lightning discharges, are used to determine the current moment waveforms of vertical lightning discharges. In order to extract this information the propagation of radio atmospherics from source to receiver must be modeled accurately, especially in view of the important ro...
متن کاملLightning sferics and stroke-delayed pulses measured in the stratosphere: Implications for mesospheric currents
[1] During the Brazil Sprite Balloon Campaign 2002–03, the vector ELF to VLF (25 Hz–8 kHz) electric and magnetic fields driven by cloud-to-ground (CG) lightning strokes at horizontal distances of 75–600 km were measured at altitudes of 30–35 km. Electric field changes were measured for each of the 2467 CG strokes detected by the Brazilian Integrated Lightning Network. ELF pulses that occur 4–12...
متن کاملELF Radiation Produced by Electrical Currents in Sprites
Measurements of ELF-radiating currents associated with sprite-producing lightning discharges exhibit a second current peak simultaneous in time with sprite luminosity, suggesting that the observed ELF radiation is produced by intense electrical currents flowing in the body of the sprite.
متن کاملDetection of daytime sprites via a unique sprite ELF signature
On August 14, 1998, 3 separate daytime sprite events were detected via a unique extremely low frequency (ELF) sprite signature. The onset of the sprite ELF signatures was delayed by 11.0-13.2 ms from positive cloudto-ground strokes which had attained exceptionally large charge moment (charge times height) changes of 39006100 C·km. It is shown that a charge moment change of 6100 C·km may have be...
متن کاملIonospheric D region remote sensing using VLF radio atmospherics
Lightning discharges radiate the bulk of their electromagnetic energy in the very low frequency (VLF, 3–30 kHz) and extremely low frequency (ELF, 3–3000 Hz) bands. This energy, contained in impulse-like signals called radio atmospherics or sferics, is guided for long distances by multiple reflections from the ground and lower ionosphere. This suggests that observed sferic waveforms radiated fro...
متن کامل