Geomagnetic Virtual Observatories

Description of GVO data product: Geomagnetic Virtual Observatories (GVO) data are derived from satellite magnetic measurements. The GVO data products consists of magnetic field time series regularly distributed in space and time. GVO time series including all field contributions, and those processed to isolate the core field, are available along with estimated errors. The GVO product are designed to make satellite data more accessible to researchers studying the physics of the core dynamo process, and related phenomenon such are secular variation, geomagnetic jerks and rapid core dynamics. In addition, the GVO product also provide valuable information to those interested in investigating magnetospheric and ionospheric magnetic signals on timescales of months and longer. GVO data products of 1, 4 and 12 month cadance are available for the Ørsted mission (1999-2005), the CHAMP mission (2000-2010), the CryoSat-2 mission (2010-2018), the Grace mission (2007-2018, 12 month only) and the Swarm mission (2014-2022). In addition, a composite GVO dataset derived from all the above missions (with the execption of Grace) are available covering 1999-2022. The GVO data products are given as CDF files providing the magnetic field components, the secular variation field components, and their associated error estimates, all provided in a global grid of 300 Geomagnetic Virtual Observatories. For each satellite zip compressed folders contains the CDFs and a ReadMe.txt file which provides details on the datasets and how these where made. References: Hammer, M.D, Finlay, C.C, and Olsen, N. (2021) Applications for CryoSat-2 satellite magnetic data in studies of the Earth's core field variations. Earth, Planets and Space, 73:73. Hammer, M.D., Cox, G. A., Brown, W. J., Beggan, C. D., & Finlay, C. C. (2021). Geomagnetic Virtual Observatories: monitoring geomagnetic secular variation with the Swarm satellites. Earth, Planets and Space, 73(1), 1-22.

GVO数据产品说明：地磁虚拟观测台（Geomagnetic Virtual Observatories，GVO）数据源自卫星磁场测量。GVO数据产品包含在时空上均匀分布的磁场时间序列。本系列既提供包含全部磁场分量贡献的GVO时间序列，也提供经处理以分离出地核磁场的序列，同时附带误差估计值。本产品旨在方便研究地核发电机过程（core dynamo process）物理学、以及地磁长期变化（secular variation）、地磁急变（geomagnetic jerks）和地核快速动力学等相关现象的科研人员更便捷地获取卫星数据。此外，GVO产品还可为关注月级及更长时间尺度磁层（magnetospheric）与电离层（ionospheric）磁场信号研究的人员提供有价值的参考信息。针对以下任务，提供1个月、4个月和12个月采样间隔的GVO数据产品：欧斯特（Ørsted）卫星任务（1999-2005年）、CHAMP任务（2000-2010年）、CryoSat-2任务（2010-2018年）、Grace任务（2007-2018年，仅提供12个月间隔数据）以及Swarm任务（2014-2022年）。此外，还提供由上述除Grace任务外所有任务数据融合得到的综合GVO数据集，时间覆盖范围为1999-2022年。GVO数据产品以通用数据格式（Common Data Format，CDF）文件形式提供，包含磁场分量、地磁长期变化场分量及其相关误差估计值，所有数据均基于包含300个地磁虚拟观测台的全球网格布设。各卫星对应的zip压缩包中包含CDF文件与ReadMe.txt说明文档，其中详细阐述了数据集详情及其构建方法。参考文献：1. Hammer, M.D.、Finlay, C.C.与Olsen, N.（2021）《CryoSat-2卫星磁场数据在地核磁场变化研究中的应用》，《地球、行星与空间》，73:73；2. Hammer, M.D.、Cox, G.A.、Brown, W.J.、Beggan, C.D.与Finlay, C.C.（2021）《地磁虚拟观测台：利用Swarm卫星监测地磁长期变化》，《地球、行星与空间》，73(1):1-22