Science of atmospheric phenomena with JEM-EUSO

The main goal of the JEM-EUSO experiment is the study of Ultra High Energy Cosmic Rays (UHECR, 10¹⁹−10²¹ eV), but the method which will be used (detection of the secondary light emissions induced by cosmic rays in the atmosphere) allows to study other luminous phenomena. The UHECRs will be detected through the measurement of the emission in the range between 290 and 430 nm, where some part of Transient Luminous Events (TLEs) emission also appears. This work discusses the possibility of using the JEM-EUSO Telescope to get new scientific results on TLEs. The high time resolution of this instrument allows to observe the evolution of TLEs with great precision just at the moment of their origin. The paper consists of four parts: review of the present knowledge on the TLE, presentation of the results of the simulations of the TLE images in the JEM-EUSO telescope, results of the Russian experiment Tatiana–2 and discussion of the possible progress achievable in this field with JEM-EUSO as well as possible cooperation with other space projects devoted to the study of TLE – TARANIS and ASIM. In atmospheric physics, the study of TLEs became one of the main physical subjects of interest after their discovery in 1989. In the years 1992 – 1994 detection was performed from satellite, aircraft and space shuttle and recently from the International Space Station. These events have short duration (milliseconds) and small scales (km to tens of km) and appear at altitudes 50 – 100 km. Their nature is still not clear and each new experimental data can be useful for a better understanding of these mysterious phenomena. [DOI: 10.1007/s10686-014-9431-0]

Global transients in ultraviolet and red-infrared ranges from data of universitetsky-tatiana-2 satellite

Light detectors sensitive to wavelength ranges 240–400nm and beyond 610nm (which we refer to, for simplicity, as the UV and Red bands) on board UniversitetskyTatiana-2 satellite have detected transient ?ashes in the atmosphere of duration 1–128ms. Measured ratio of the number of Red photons to the number of UV photons indicates that source of transient radiation is at high atmosphere altitude (>50km). Distribution of events with various photon numbers Qa in the atmosphere found to be different for “luminous” events Q_a = 10²³ – 10²⁶ (with exponent of differential distribution –2.2) and for “faint” events Q_a = 10²¹ – 10²³ (with exponent
0.97). Luminous event parameters (atmosphere altitude, energy released to radiation, and temporal pro?les) are similar to observed elsewhere parameters of transient luminous events (TLE) of elves, sprites, halo, and gigantic blue jets types. Global map of luminous events demonstrates concentration to equatorial zones (latitudes 30ºN to 30ºS) above continents. Faint events (with number of photons Q_a = 10²⁰ – 5·10²¹) are distributed more uniformly over latitudes and longitudes. Phenomenon of series of transients registered every minute along satellite orbit (from 3 to 16 transients in one series) was observed. Most TLE-type events belonged to series. Single transients are in average fainter than serial ones. Some transients belonging to series occurs far away of thunderstorm regions. Origin of faint single transients is not clear; several hypothetical models of their production are discussed.