For the first time, Chinese geophysicists used ground-based radar to observe in real time the formation of equatorial plasma bubbles, which are difficult to detect with profilers. The observation was made at a distance of almost 10 thousand kilometers.

Radar LARID – A long-range, low-latitude ionospheric radar installed on Hainan Island with a detection range of 9,600 kilometers. Conventional radars have difficulty “catching” targets below the horizon due to the curvature of the planet. LARID overcomes this problem by emitting powerful electromagnetic waves that bounce off the ionosphere and ground, allowing it to travel long distances.

The Chinese radar operates in the 8-22 megahertz frequency range and is equipped with two radar subsystems: one facing east and the other facing west. Each has 24 receiving and transmitting antennas.

LARID uses a fully digital phased array antenna system that allows detection frequency, range, scan area and radar tuning to be adjusted in real time as required.

The Chinese radar has a unique ability. It can detect equatorial plasma clouds, an “anomalous atmospheric phenomenon” that disrupts satellite communications and GPS systems and causes interference in the ionosphere. These plasma bubbles opened up long ago and are usually observed at low latitudes. They form when a large number of electrons are suddenly ejected from the ionosphere, creating large “electron-coupled” regions.

Until now, the observation of these bubbles has been fraught with difficulties. However, LARID has overcome these tasks and thus, according to Chinese scientists, has become the first radar in the world to detect these anomalies in the atmosphere. When the Chinese radar emits strong electromagnetic waves, they collide with the equatorial plasma bubbles, as a result, part of the signal is reflected back and received by the LARID antenna array.

During the solar magnetic storm on November 4-6, 2023, the LARID system successfully detected radar echoes from plasma bubbles forming over North Africa and the central Pacific Ocean. By analyzing these signals, Chinese scientists were able to observe the formation of plasma bubbles and track their movements over the Egyptian pyramids of Giza and the Midway Islands in real time. In other words, geophysicists monitored the anomaly from a distance of almost 10,000 kilometers, an unprecedented detection range. The discovery was reported by the South China Morning Post, citing the Institute of Geology and Geophysics of the Chinese Academy of Sciences.

Chinese researchers believe that their discovery will be important for global communication and navigation systems, allowing to reduce the negative impact of plasma bubbles on satellite signals. In the near future, China may build three or four more LARID-like radars in low-latitude regions. Such a network would provide continuous real-time monitoring of equatorial plasma bubbles.

Due to its insufficient resolution, LARID is not suitable for detecting military targets such as fighter jets or ships. However, according to official Chinese media, the local military is actively using over-the-horizon radars with technologies similar to LARID, which were able to successfully locate fifth-generation American F-22 Raptor stealth fighters.