Chinese Meridian Phase II sets new benchmark in global space weather monitoring

Initiated in 2019, CMP Phase II implemented a strategic "two vertical, two horizontal" cross-shaped monitoring network aligned along the 100 E and 120 E longitudes, and the 30 N and 40 N latitudes. The expansion incorporated 16 additional observation sites alongside the original 15 Phase I locations, enabling enhanced three-dimensional detection of space weather events, including solar activity and terrestrial atmospheric reactions.

CMP Phase II introduced several advanced technological systems:

Foremost among these is the Daocheng Radio Telescope (DART), a circular antenna array that captures three-dimensional images of the solar corona across a 10-solar-radius view, facilitating detailed monitoring of solar behavior.

Additionally, the deployment of a unique metastable helium lidar network allows for sustained vertical profiling of atmospheric metastable helium, covering altitudes from 200 to 1000 kilometers.

The project also established the world's inaugural tristatic incoherent scatter radar system, utilizing phased array technology to conduct ionospheric computed tomography (CT) and generate expansive 3D scans over thousands of kilometers.

Moreover, the Chinese Dual Auroral Radar Network (CN-DARN), operating in the high-frequency band, provides round-the-clock surveillance of ionospheric movement across Asia, with coverage spanning more than 4,000 km from north to south and 10,000 km from east to west.

Another key development is China's first facility specifically engineered to reconstruct 3D models of solar wind formations, significantly improving capabilities for forecasting interplanetary space conditions.

Following its initial trials, CMP Phase II has proven highly effective. It notably recorded the intense geomagnetic storm of May 2024, delivering accurate, real-time datasets essential for analyzing atmospheric responses to space weather disturbances.

WANG Chi, the Principal Investigator for CMP Phase II, emphasized the national significance of the project, stating: "By unifying global-scale monitoring, we are building a critical shield against space weather threats and offering innovative solutions to global scientific challenges."

Looking ahead, China is spearheading the International Meridian Circle Program (IMCP), which will establish a monitoring chain along 180 degrees of longitude from 120 E to 60 W. This global initiative will support continuous, all-latitude space weather observations, addressing cross-border challenges such as solar storms and geomagnetic disturbances, and underscores China's commitment to international cooperation in space science.