New Chains of Space Weather Monitoring Stations in China

Abstract

To develop an understanding of near-Earth space’s response to solar activities and to eventually enhance the success of space weather predictions, it is crucial to make synergetic observations of the entire environment from the Sun to the Earth as a system. Since the beginning of the space era, direct observations by satellites have become a much needed means toward this end. However, ground-based observations also have advantages and serve as a counterpart to those made in space. For example, instruments on the ground are much less expensive and easier to repair than those on satellites. Groundbased observations provide continuous highresolution data not subject to the limitation of the downlink data rate from satellites to ground receiving stations. Also, because some observations have been made from Earth for hundreds of years, society has long and continuous records of quantities such as geomagnetic field variations, measurements of relative ionospheric opacity, and sunspot observations. Data from spacecraft, on the other hand, go back only a few decades. China has a total land area of about 9,600,000 square kilometers, with geomagnetic locations covering middle to low latitudes. The first geomagnetic observatory in China was constructed in Beijing in 1870 by Russians, but it ceased working in 1882. China briefly participated in the International Geophysical Year (1957–1958) and started to explore the upper atmosphere using rockets and balloons in the 1960s. Though research at government institutions and universities picked up in the late twentieth century, the ability to monitor the geospace environment and capture the evolution and characteristics of the weather in geospace above China is still insufficient today. Not only is China’s large population increasingly reliant on space-based technologies, but there are also not enough locations across the country where space weather conditions are monitored. This limits Chinese scientists’ understanding of the basic physical processes in geospace and their ability to make accurate predictions of adverse space weather for their country’s citizens. To acknowledge the needs of both basic science and useful space weather operations, a ground-based program to monitor China’s geospace environment is currently under way. Called the Meridian Space Weather Monitoring Project (or Chinese Meridian Project), the effort consists of a chain of 15 ground-based observatories located roughly along 120°E longitude and 30°N latitude. Each observatory is equipped with multiple instruments to measure key parameters such as the baseline and timevarying geomagnetic field, as well as the middle and upper atmosphere and ionosphere from about 20 to 1000 kilometers. Starting in 2011, the project will collect data for at least 11 years, providing the wide-range, continuous, and multiparameter data sets needed to guide model developments, which in turn will better describe and predict the characteristics and dynamics of the geospace environment.