Citation: | Li, Y. J., Feng, Y., Zhang, S. Q., Liu, S., Zhang, J. Y., and Wei, G. C. (2023). The study of geomagnetic jerk from 2010 to 2021 based on hourly mean data from global geomagnetic observatories. Earth Planet. Phys., 7(1), 39–48. doi: 10.26464/epp2023016 |
The secular variation in the global geomagnetic field was analyzed in terms of the annual differences in monthly means by using the hourly mean data from 18 foreign (outside China) observatories of the World Data Center (WDC) for Geomagnetism from January 2010 to January 2020 as well as 9 observatories in the Geomagnetic Network of China from January 2015 to April 2021. In addition, according to the correlation of noisy components from the observatories, a covariance matrix was constructed based on residuals between observations and the CHAOS-7.4 model to remove external contamination. Through a comparison before and after denoising, we found that the overall average standard deviations were reduced by 29.97% in China and by 41.4% outside China. Results showed the correlation coefficient between external noise (mainly the magnetosphere ring current) and the