Lightning and Electromagnetic Phenomena

A new instrument has been developed and deployed for sensitive reception of broadband extremely low frequency (ELF) (defined in this paper as 300-3000 Hz) and very low frequency (VLF) (defined in this paper as 3-30 kHz) radio signals from natural and man-made sources, based on designs used for decades at Stanford Univ…

• UMRAN SAVAŞ İNAN

We present the first global distribution of the average estimated peak currents in negative lightning flashes using 1 year of continuous data from the Vaisala global lightning data set GLD360. The data set, composed of 353 million flashes, was compared with the National Lightning Detection NetworkTM for peak current a…

• UMRAN SAVAŞ İNAN

Lightning discharges generate broadband electromagnetic pulses with a peak component in the very low frequency (VLF; 3–30 kHz) range. VLF waves propagate through the Earth‐ionosphere waveguide with relatively low attenuation, enabling the detection of these radio atmospherics at great distances from the lightning disc…

• UMRAN SAVAŞ İNAN

Extremely low frequency (ELF) and very low frequency (VLF) observations have formed the cornerstone of measurement and interpretation of effects of lightning discharges on the overlying upper atmospheric regions, as well as near‐Earth space. ELF (0.3–3 kHz) and VLF (3–30 kHz) wave energy released by lightning discharg…

• UMRAN SAVAŞ İNAN

Terrestrial gamma‐ray flash (TGF) production has been modeled by several emission mechanisms. In spite of extensive studies of these mechanisms and the existing satellite data, significant uncertainties exist about the nature of the source. In this paper, we present a method to develop approximate production‐mechanism…

• UMRAN SAVAŞ İNAN

Due to the challenges facing many utilities worldwide as a result of deregulation, the demand and importance of accurate fault location in distribution Systems has increased, principally to minimise line outages through effecting repairs expeditiously. The paper presents a novel approach in single-ended fault location…

• YILMAZ ASLAN

Since the late 1970s, intensive efforts have been made to utilize renewable energy sources to generate electric power. On the other hand, economical pressure experienced in recent years has led to the development of high efficiency combined heat and power schemes to use the normally wasted heat to generate electric po…

This work the combined electrical and thermal stresses of the 154 kV XLPE power cable used in the underground power transmission in Turkey. The dependence of aging on electrical and thermal stresses is given by a straight line in a certain range of electric field (E) values which indicates that the aging is a thermoch…

• NURSEL CAN

DEMETER spacecraft detects short bursts of lightning‐induced electron precipitation (LEP) simultaneously with newly‐injected upgoing whistlers, and sometimes also with once‐reflected (from conjugate hemisphere) whistlers. For the first time causative lightning discharges are definitively geo‐located for some LEP burst…

• UMRAN SAVAŞ İNAN

Very Low Frequency (VLF, 3–30 kHz) radio waves emitted from ground sources (transmitters and lightning) strongly impact the radiation belts, driving electron precipitation via whistler‐electron gyroresonance, and contributing to the formation of the slot region. However, calculations of the global impacts of VLF waves…

• UMRAN SAVAŞ İNAN

The production of terrestrial gamma ray flashes (TGFs) requires a seed energetic electron source and a strong electric field. Lightning leaders naturally provide seed electrons by cold runaway and strong electric fields by charge accumulation on the channel. We model possible TGF production in such fields by simulatin…

• UMRAN SAVAŞ İNAN

We consider the possible production of persistent ionization at low altitudes ( h ≤ 70 km) by giant blue jets (GBJ), using a new five constituent model of stratospheric/lower‐ionospheric chemistry. Results indicate substantial ionization at h < 50 km, which exhibits an initially rapid (few seconds) recovery due to ele…

• UMRAN SAVAŞ İNAN