Preliminary analysis of the Changvan neutron monitor operation in latitude surveys during 2019-2020

Abstract

Within our solar system, space weather is influenced by the solar wind and the interplanetary magnetic field carried by the solar wind plasma. Severe solar storms can expose people to increased radiation levels, shut down electrical systems, and interfere with radio signals. Space weather probably affects the weather and climate on our planet, but we do not yet have a precise understanding of the influence. Some aspects of space weather can be monitored at ground level with a detector, such as a “neutron monitor,” that measures cosmic rays from outer space. We have developed a portable “Changvan” neutron monitor to investigate the energy spectrum of cosmic rays and its solar modulation, i.e., variations over the typically 11-year sunspot cycle. The Changvan monitor located inside the insulated shipping container comprises three proportional counters in the standard-design neutron monitors, but the central counter is deficient in the lead producer. This monitor records counting rates during passage through a range of geomagnetic latitudes, which this technique is called “latitude survey.” The ultimate goal of the latitude surveys is to help accurately interpret data from every neutron monitor in a space environment that is always changing. In this work, we show a preliminary analysis of Changvan monitor data collected from two latitude surveys during 2019-2020 on the Chinese icebreaker MV Xue Long from Shanghai, China to Zhongshan station, Antarctica and back. A strong anti-correlation can be observed between the Changvan monitor count rate and barometric pressure.