The dataset is composed of the Eyrewell (EYR) geomagnetic vector field measurements with the highest resolution available for 2000 to 2017, a time period of interest for the research publications by Rodger et al. (2017), Smith et al. (2021), and Hartinger et al. (2023). The resolution varies between 20-second (20s), 5-second (5s), and 1-second (1s). The data are processed, except for the 2002 and 2003 data. A new data recording system was installed on 16 February 2005 and upgraded to a faster one on 26 February 2010. The observatory location changed by 6 km on 3 December 2013. Adjustments need to be applied to get a continuous record. The values for the difference between the old and new site are D = 2.73 arcmin, I = 0.58 arcmin, and F = 14.7 nT. Overview: 2000 20s resolution 2001 20s resolution 2002 5s resolution (raw data) 2003 5s resolution (raw data) 2004 20s resolution 2005 5s & 20s resolutions 2006 5s resolution 2007 5s resolution 2008 5s resolution 2009 5s resolution 2010 1s & 5s resolutions 2011-onwards 1s resolution The 1-second data since 14-Sep-2011 is available for download on INTERMAGNET. https://intermagnet.github.io/ The dataset was used to create a sub-dataset that contains only the horizontal magnitude of the EYR geomagnetic field measurements provided in units of nT at 5s resolution. The sub-dataset is available in a MATLAB format on Zenodo. EYR5sec10292003.mat. https://doi.org/10.5281/zenodo.7261515 Cite dataset as: GNS Science (2023). Eyrewell (EYR) best resolution data 2000 - 2017 [Dataset]. https://doi.org/10.21420/BVEZ-T482

2022 Definitive 1-minute Scott Base (SBA) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories SBA in 2022 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected following INTERMAGNET guidelines. The data was submitted to INTERMAGNET in May 2023 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/axhk-e303 Cite as: Thornton, M., Goodyear, G., Shaw, S. (2022). 2022 Definitive 1-minute Scott Base (SBA) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/axhk-e303

The dataset is composed of the original sheets on which the fields were recorded by light on photographic paper. Each sheet holds 24 hours of three recorded magnetic field components. Most of the components were labelled XYZ; some were labelled DHZ (e.g. 1991 magnetograms), and others were not labelled at all (e.g. 1966 magnetograms). Scott Base (SBA) 1957 – 1991 DOI: https://doi.org/10.21420/3KT9-3M51 Cite as: GNS Science. (2022). Scott Base (SBA) paper magnetograms . GNS Science. https://doi.org/10.21420/3KT9-3M51

2021 Definitive 1-minute Scott Base (SBA) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories SBA in 2021 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected following INTERMAGNET guidelines. The data was submitted to INTERMAGNET in May 2022 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/b0yc-rk98 Cite as: Thornton, M., McGaw, J., Tran, H., Shaw, S. (2021). 2021 Definitive 1-minute Scott Base (SBA) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/b0yc-rk98

Preliminary 1-second and 1-minute Scott Base (SBA) data are submitted to INTERMAGNET in a standardized file format (IAGA-2002) every hour. The data can be downloaded via a free web access provided by INTERMAGNET at http://www.intermagnet.org/data-donnee/download-eng.php (Data Type: ‘provisional’). 1-minute (Sample Rate: ‘minute’) ‘provisional’ SBA data are available since 1996. 1-second data (Sample Rate: ‘second’) ‘provisional’ SBA data are available since 2012. DOI: https://doi.org/10.21420/TTQ0-SR11 Cite data as: GNS Science. (2022). Preliminary 1-second and 1-minute data from Scott Base (SBA) [Data set]. INTERMAGNET. https://doi.org/10.21420/TTQ0-SR11

2018 Definitive 1-minute Scott Base (SBA) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories SBA in 2018 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2019 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/039F-XE27 Cite as: Petersen, T., & GNS Science. (2019). 2018 Definitive 1-minute Scott Base (SBA) data [Data set]. INTERMAGNET. https://doi.org/10.21420/039F-XE27

2014 Definitive 1-minute Scott Base (SBA) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories SBA in 2014 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2015 and passed the INTERMAGNET reviewing process. DOI: https://doi.org/10.21420/7DM8-ZM49 Cite as: Petersen, T., & GNS Science. (2015). 2014 Definitive 1-minute Scott Base (SBA) data [Data set]. INTERMAGNET. https://doi.org/10.21420/7DM8-ZM49

2018 Definitive 1-minute Apia (API) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatory Apia in 2018 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2019 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/CNMJ-V311 Cite as: Petersen, T., GNS Science, Samoa Meteorology Division, & USGS. (2019). 2018 Definitive 1-minute Apia (API) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/CNMJ-V311

The dataset is composed of the original sheets on which the fields were recorded by light on photographic paper. Each magnetogram sheet holds a record of 24 hours. Normally the magnetic field components H and D are recorded; some years in addition do have recordings of the Z component. Apia (API) 1907 – 1913 Apia (API) 1932 – 1955 There are magnetograms for 1956 - 1994, but they are not complete and the contents need yet to be specified. For 1907 - 1913, magnetograms for H and D are mostly complete. The years 1908 - 1911 have some additional magnetograms that might be for the Z component. GNS Science does not hold records from 1914 to 1931. After the long gap, there are fewer magnetograms for 1932 - 1936; from 1937 - 1955, each year has magnetograms for H, D & Z for most days. There are Apia rapid runs available for 1956 - 1978, and 1983-1986, and Apia Wider Range (WR) from 1977, 1979, 1980, 1983, 1985, 1986. Some of the records were received from the University of Göttingen, Germany, who originally established this magnetic station. DOI: https://doi.org/10.21420/WYV2-6K33 Cite as: GNS Science. (2022). Apia (API) paper magnetograms . GNS Science. https://doi.org/10.21420/WYV2-6K33

This database documents the short-term and long-term fluctuations in the Earth's regional (New Zealand) magnetic field captured by magnetic observatories. Magnetic Observatories record variations with time of the earth’s magnetic field at a fixed point. A magnetic field is completely described by three components, these are usually HDZ or XYZ, where H is the horizontal magnetic field strength, D is the declination or angle between the direction of the magnetic field and true north, Z is the vertical magnetic strength, and X and Y are the magnetic field strengths in the true north and east directions. It is also common to record F, the total magnetic field strength, on a separate instrument, although that can be calculated from HDZ or XYZ. New Zealand operates magnetic observatories in Canterbury (the Eyrewell Geomagnetic Observatory that succeeded the Christchurch and Amberley observatories and is now located at West Melton) and Scott Base in Antarctica, and supports the Apia observatory in Samoa. Eyrewell (EYR), Scott Base (SBA) and Apia (API) geomagnetic observatories are important contributors to the ~120 station INTERMAGNET global network that monitors the Earth’s magnetic field. All observatories follow INTERMAGNET requirements and standards. The continuous part of the data collection is run by an automated system that is recording data every second. Manual measurements are conducted by a local observer for 1 hour once every week. EYR also relies on data recorded at a joined GeoNet site located at Summerhill (Canterbury). Raw 1-second data in miniseed format is archived for all three observatories plus for the Summerhill site. Preliminary 1-second and 1-minute data are submitted to INTERMAGNET in a standardized file format every hour. Definitive 1-minute data for EYR, SBA and API is being submitted to INTERMAGNET annually. Before INTERMAGNET definitive data are being published an international multi-step reviewing process is being applied to ensure international standards are being met. K-index values are calculated from data recorded at EYR and its predecessor Amberley (AML). Historic paper records are being stored, with some of them being scanned into digital images.