Alshuaili I.Y.K., Issa Salim Aal Alshaikh, Albusaidi Q., Akindi A. «Aurora in Oman: observations and images» Солнечно-земная физика, 11, № 1, с. 109-112 (2025)

The Sun showed extraordinary activity related to sunspot area 3664 on May 8–10, 2024, resulting in solar flares considered the most intense in the current solar cycle. Auroras occurred in several regions around the world. Early on May 12, 2024 near the highest peak in the Sultanate of Oman, a team of Omani astrophotography enthusiasts documented the rare event ever observed in this region. Auroras often occur along the so-called auroral oval zones around the geomagnetic poles, where Earth's magnetic field directs charged particles penetrating from the solar wind. This takes place when a cloud of charged particles is thrown toward Earth by a large explosion on the Sun. Sometimes, these particles can make the aurora visible in places where it is exceedingly rare throughout recorded history. The observation from the mountain Jebel Shams, situated far from the polar regions (23 degrees north of the equator), offers a unique chance to study such an event in a region where auroras are exceptionally rare. We explore the factors contributing to the observed aurora in Oman, including geomagnetic conditions and the role of sunspot region AR3664 in solar activity along with local conditions in Oman that contributed to the visibility of this aurora. Understanding this dynamics can enhance our knowledge of the mechanisms driving auroral visibility at lower latitudes and provide valuable insights into the global impact of solar storms. This study also emphasizes how crucial it is to record auroras in regions like the Arabian Peninsula, where they are rarely documented.

Ivanov A.I., Shcherbakov Yu.M. «Control block acoustic optical modulator» Приборы и техника эксперимента, 35, № 1, с. 241 (1992)

The block was designed for forming radiofrequency signal the amplitude of which was proportional to input signal. Carrier frequency was 80±0.5 MHz (160±1 MHz); frequency drift and extraneous frequency modulation was <0.5%; maximal peak output power was 5 Wt (2.5 Wt); manual adjustment of output power was 10 dB; modulation depth of output radiofrequency signal was 99%; non-linearity of modulation property in dynamic range was 20dB±5%; modulation frequency band by level of 1 dB was 0-10 MHz; amplitude of modulating signal at input resistance of 75 Ohm was 0–1.4 V; amplitude stability of output signal in case of any fixed level output power was ±2%.

Ivanov V.V., Labutin S.A., Mel'nikov V.I. «Computer acoustic diagnostic system for two-phase flows» Приборы и техника эксперимента, 36, № 1, с. 238-239 (1993)

The authors describe a system determining the local and volume steam content, the velocity of the motion and the size of steam or gas bubbles in a liquid flow. The complex includes four acoustic converters, a measuring part connected with a computer and made in the form of a plate located inside the computer and a package of applied programmes. The measurement of the parameters of two-phase flows is based on the measurement of a signal passing from a radiator of an acoustic pulse to an acoustic receiver. The main technical characteristics are given.