https://www.cas.cn/cm/202602/t20260212_5101730.shtml
China’s Space Environment Ground-Based Integrated Monitoring Network, also known as the “Meridian Project”, is based on six high-frequency coherent scattering radars at three stations in Longjing, Jilin; Siziwang Banner, Inner Mongolia; and Hejing, Xinjiang.
The nationwide sky-observation network monitors space weather and is meant to serves as a protective umbrella for humanity against space weather disasters.
In the 1990s, when foreign countries were racing to launch solar monitoring satellites, Academician Wei Fengsi of the Chinese Academy of Sciences proposed a differentiated approach: utilizing ground stations to build a “cross”-shaped ground-based monitoring chain along 120 degrees east longitude and 30 degrees north latitude. 30 years, the “well”-shaped array is laid out along 100° and 120° east longitude and 30° and 40° north latitude. With 31 integrated stations and 282 sets of equipment, stretching from Shanghai in the east to Lhasa in the west, from Mohe in the north to Hainan in the south, and extending to Zhongshan Station in Antarctica, it monitors the changing weather across 150 million kilometers from the sun to the earth.
The value of this network lies in its ability to “see” processes and details that others cannot. It has achieved a three-dimensional monitoring system of encompassing the geomagnetic field, the middle and upper atmosphere, and the ionosphere; and focusing on four key regions—polar regions, mid-latitudes, low latitudes, and the Qinghai-Tibet Plateau.
The Meridian Project team has also achieved breakthroughs in basic scientific research, such as the “space typhoon” phenomenon.
https://www.nature.com/articles/s41467-021-21459-y
At an altitude of 3,800 meters on the plateau, the Meridian Project team built the world’s largest aperture synthesis solar radio telescope. In the Gobi Desert, the Meridian Project team built China’s first interplanetary scintillation telescope which achieve three-station, dual-frequency observations. Across a vast area spanning northern China, the Meridian Project team built a mid-latitude high-frequency radar network, filling an international gap. In collaboration with the international super-polarized radar network, it provides the first complete imaging observation of the ionospheric convection evolution process during geomagnetic storms.
Unlike many large-scale scientific projects, the Meridian Project’s equipment is distributed throughout the country, making its construction and management far more complex than imagined. Today, at the Meridian Building Operations and Control Center in Huairou, Beijing, data from 282 devices across the country scrolls in real time on a large screen. Once the forecasting center on the third floor detects an anomaly, warning information is instantly issued through multiple channels.
Space weather is a global challenge; the impact of solar storms knows no borders. Based on the Meridian Project’s globally leading monitoring network, the Meridian Project team initiated and led the “International Meridian Circle” mega-science project. This ambitious concept aims to unite countries along the 120°E and 60°W meridians—the only meridian circle on Earth capable of forming a closed loop—to jointly construct a 24/7 global space environment monitoring chain encircling the Earth, achieving three-dimensional observation of the Sun-Earth space environment across all latitudes, in all weather conditions, and without sunset. To date, the Chinese team has attracted 51 top international organizations and foreign research institutions, including the International Council for Space Research, the Asia-Pacific Space Cooperation Organization, the Brazilian National Institute for Space Research, King Mongkut’s University of Technology Laksana (TMR) in Thailand, and the Pyrenees Observatory in France, signing cooperation agreements or confirming cooperation intentions. More than a thousand sets of monitoring equipment have been jointly mobilized, and a truly global space weather observation alliance is beginning to take shape.
The initiative aims to deeply understand the chain of changes in the Sun-Earth space. It will not only deepen human understanding of the fundamental physical processes of space weather but also strive to build a large-scale space weather model and high-precision forecast products, providing reliable public goods for global satellite security, communication assurance, and disaster prevention and mitigation. According to the plan, this large-scale scientific project will run for at least 11 years, covering a complete solar activity cycle, to complete continuous detection and research and build a space weather community with broad participation from scientists worldwide.
