Continuous data recorded by New Zealand's Geomagnetic Observatories SBA processed at 1-minute sampling and baseline (absolute values) corrected. The data is being submitted to INTERMAGNET annually (submitted by July 1st for the previous year’s data Jan 1 to 31 Dec). SBA data since 1-Jan-1996 Before the definitive data for each year is being published via INTERMAGNET an international multi-step reviewing process is being applied to ensure international standards are being met. DOI https://doi.org/10.21420/CC3M-2D40 Cite as: GNS Science. (1996). Definitive 1-minute Scott Base (SBA ) data [Data set]. GNS Science, INTERMAGNET. https://doi.org/10.21420/CC3M-2D40

2018 Definitive 1-minute Eyrewell (EYR) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories EYR 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/10.21420/65S4-TW09 Cite as: GNS Science, Petersen, T., Plank, G., & Plank, J. (2019). 2018 Definitive 1-minute Eyrewell (EYR) data [Data set]. INTERMAGNET. https://doi.org/10.21420/65S4-TW09

2016 Definitive 1-minute Apia (API) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatory Apia in 2016 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2017 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/BWW7-PN94 Cite as: Petersen, T., GNS Science, Samoa Meteorology Division, & USGS. (2017). 2016 Definitive 1-minute Apia (API) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/BWW7-PN94

2015 Definitive 1-minute Apia (API) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatory Apia in 2015 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2016 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/VDYN-6M33 Cite as: Petersen, T., GNS Science, Samoa Meteorology Division, & USGS. (2016). 2015 Definitive 1-minute Apia (API) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/VDYN-6M33

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

K-index values calculated from Amberley (AML) and Eyrewell Geomagnetic Observatory (EYR) data. The K-index is a measure of disturbances in the Earth’s magnetic field which was introduced by Bartels et al. (1939), that is recognised as a good indication of the strength of magnetic storm activity caused by the sun. It is based on the maximum fluctuations of horizontal components recorded in each 3-hour interval, so there are eight values each day. The scale is from 0 to 9, in an approximately logarithmic fashion, with the nT value required for the maximum value of 9 being a parameter of the observatory. Originally the fluctuations were measured on paper chart records, measuring short-term variations by subtracting the effects of the slower daily variations, but with digital records, algorithms are used to calculate only the effects of short-term variations. At Eyrewell, the manual method was used up until 1995, while from 1996 onwards, an algorithm developed by Hattingh et al (1989) at the Hermanus Magnetic Observatory was used (Tomlinson, 1995). The Hemanus algorithm is available from the website http://isgi.unistra.fr/softwares.php. Available data: Amberley (AML) 1951 – 1977 Eyrewell (EYR) 1978 – present 1932 – 1977 planetary Kp values (https://www.gfz-potsdam.de/en/kp-index/) were produced based on data from the Amberley observatory as a representative for the Southern Hemisphere. Toolangi only joined in 1972 (and was replaced by Canberra in 1981). DOI: https://doi.org/10.21420/PJ1Y-6M90 Cite as: GNS Science, & Hurst , T. (2021). EYR k-index values [Data set]. GNS Science. https://doi.org/10.21420/PJ1Y-6M90

2020 Definitive 1-minute Scott Base (SBA) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatories SBA in 2020 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July 2021 and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/2A9G-6S83 Cite as: Thornton, M., Tran, H., McGaw, J., Dobson, W. (2020). 2020 Definitive 1-minute Scott Base (SBA) data [Dataset]. GNS Science, INTERMAGNET. https://doi.org/10.21420/2A9G-6S83

1999-2013 Definitive 1-minute Apia (API) data is continuous 1-second data recorded by New Zealand's Geomagnetic Observatory Apia in the period between 1999-2013 that was processed at 1-minute sampling, cleaned (spikes removed) and baseline (absolute values) corrected. The data was submitted to INTERMAGNET in July of the following year and passed the INTERMAGNET reviewing process. DOI https://doi.org/10.21420/23X1-4N43 Cite as: GNS Science, Samoa Meteorology Division, & USGS . (2014). 1999-2013 Definitive 1-minute Apia (API) data. GNS Science, INTERMAGNET. https://doi.org/10.21420/23X1-4N43

This database documents fluctuations in the Earth's regional (New Zealand) magnetic field measured before the age of digital records. New Zealand operates magnetic observatories in Canterbury (the Eyrewell Geomagnetic Observatory located at West Melton) and Scott Base in Antarctica, and supports the Apia observatory in Samoa. Observatories in the present days provide a record of temporal changes of the magnetic field, recording the three components of the magnetic field every second. Eyrewell (EYR), Scott Base (SBA) and Apia (API) geomagnetic observatories.

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.