1. New type of electromagnetic emission

A new type of electromagnetic emission, having a form of the noise band with few hours durations in the range of 0.5-5 Hz and magnetic field intensity at about 10 pT, is discovered.

This emission is appeared quite regularily during the summer time and after the local noon. At the equinox the decrease of activity is observed. During the winter time the emission is practically not observed. The main development of the emission takes place in between 15 and 18 LT, and is terminated in sunset.

Spectral density maximum of the emission is reached at 1-2 Hz, and is practically not shifted during the course of day or season. Signal to noise ratio in the maximum of the spectrum is an order of 10 dB. The behavior of the H and D components of the magnetic field have no any significant difference.

Ðreliminary picture of the daily and seasonal emission distribution demonstrates direct dependence of the emission on local thermal regime of the Earth’s atmosphere. Thus, it is expediently to call this type of the emission as “thermal short-period geomagnetic emission”

Temporal distribution of the emission has no any correlations with Kp index, which characterized magnetospheric disturbances.

All results taking together permit to suggest, that discovered electromagnetic emission is related with local heating of the Earth’s atmosphere. Without doubt that discovering of the new unknown short-period geomagnetic emission is a contribution to the understanding of nature of electromagnetic field of the Earth.

New mechanism of magnetic field amplification in weakly ionized plasma.

A new nonlinear transformation mechanism of an acoustic type disturbance into electromagnetic signal in inhomogeneous weakly ionized collisional plasma was developed. The possibility of electromagnetic signal amplification was demonstrated. The result can be applied for the development of additional methods to estimate power of underground explosions.

New mechanism for Farley-Buneman instability in the midlatitude ionosphere.

In order to understand the origin of large electric fileds which can excite the FB-instability in the midlatitude ionosphere a quantitative model that relates to a local polarization process acting inside sporadic E layer was presented