IGRF12和WMM2015模型在中国区域的精度评估及其适用性分析

利用中国大陆区域35个地磁基准台站2008~2015年的观测数据，结合高精度的地壳磁场模型NGDC-720，计算各台站观测值和地磁场模型值7个要素之间的差值。通过引入均方根误差，评估最新的国际地磁参考场模型IGRF12和世界地磁模型WMM2015在中国区域的精度及其适用性。结果表明，IGRF12模型与台站年均值的一致性吻合较好，但对于不同台站，IGRF12模型误差相差较大。WMM2015和IGRF12模型误差具有相似的空间分布特征，且地磁各要素差值的最大值、最小值和均方根误差十分接近，其中地磁偏角和总磁场强度的均方根误差优于16'和100 nT。因此，在研究中国区域地磁异常时，IGRF12或WMM2015模型均可作为主磁场改正的参考背景场。

Accuracy Evaluation and Applicability of IGRF12 and WMM2015 Model in Chinese Mainland

In this paper, we calculate the differences of a geomagnetic field between observatories and the main magnetic field by using NGDC-720 model and observed data collected at 36 stations from 2008 to 2015 in the Chinese mainland area. The accuracy and applicability of the IGRF12 and WMM2015 models were evaluated with the RMSE. The results suggest that:the IGRF12 model is in good agreement with the annual mean value of geomagnetic observatories; but for different stations, the precision of IGRF12 model presents a huge difference. The model error in IGRF12 and WMM2015 have similar spatial distribution characteristics, and the maximum, minimum, and as root mean of magnetic elements are very close to one another. The RMSE of declination and the total magnetic field were 16'and 124.96 nT. Therefore, in studies of regional geomagnetic anomalies, regardless of the IGRF12 or WMM2015 as main magnetic field, both are feasible.