We study the geomagnetic activity Ap-index in relation to sunspot number and area for the interval covering Solar Cycles 17 to 24 (1932 – 2019), in view of the availability of data for the Ap-index from 1932 on, in order to predict the amplitude of Sunspot Cycle 25. We examine the statistical relationship between sunspot-maximum amplitude and Ap-index, and similarly that between sunspot area and Ap-index. We apply the \(\chi ^{2}\)-test for the best fit between two parameters and obtain the correlation coefficient. We also derive the standard deviation for the error limits in the predicted results. Our study reveals that the amplitude of the Sunspot Cycle 25 is likely to be \(\approx 100.21 \pm 15.06\) and it may peak in April \(2025\pm 6.5\) months. On the other hand, the sunspot area will have maximum amplitude \(\approx 1110.62 \pm 186.87\) μ Hem and may peak in February \(2025\pm 5.8\) months, which implies that Solar Cycle 25 will be weaker than or comparable to Solar Cycle 24. In view of our results as well as those of other investigators, we propose that the Sun is perhaps approaching a global minimum.

考虑到1932年以来的Ap指数数据，我们研究了太阳活动周期17至24（1932 – 2019）期间与太阳黑子数和面积相关的地磁活动Ap指数，以便预测太阳黑子周期25的振幅。我们研究了黑子最大振幅与Ap指数之间的统计关系，以及类似的太阳黑子面积与Ap指数之间的统计关系。我们应用\（\ chi ^ {2} \）-测试来获得两个参数之间的最佳拟合，并获得相关系数。我们还可以得出预测结果中误差极限的标准偏差。我们的研究表明，太阳黑子周期25的振幅可能为\（\大约100.21 \ pm 15.06 \），并且可能在4月达到峰值（\ 2025 \ pm 6.5 \）个月。另一方面，太阳黑子区的最大振幅为\（\大约1110.62 \ pm 186.87 \）μHem， 并且可能在2月\（2025 \ pm 5.8 \） 月份达到峰值，这意味着太阳周期25将弱于或可以与太阳周期24相比较。鉴于我们以及其他研究人员的结果，我们建议太阳可能正在接近全球最低水平。