This dataset contains 1-second geomagnetic vector and scalar data from the magnetometer station Macapa. The data is from 15-Nov-2019 to 07-Dec-2019, from 07-Feb-2020 to 05-Apr-2020, and from 09-Oct-2020 to 21-Nov-2020. The data files follow the IAGA-2002 data format. The IAGA format description is copied from https://www.ncei.noaa.gov/services/world-data-system/v-dat-working-group/iaga-2002-data-exchange-format and from https://www.ncei.noaa.gov/sites/default/files/2022-07/IAGA%202002%20July%202003%20Revision.txt. Both documents were downloaded on 2024-08-11 and are available here as IAGA_2002_file_format_description_2024-08-11.pdf.
The data themselves are described in Mendel Martins et al. (2024).
This dataset comprises the PCEEJ equatorial electrojet model current intensity values (mA/m). The PCEEJ is an empirical model based on the principal component analysis of satellite and ground equatorial electrojet data, described in detail in Soares et al. (2022), to which this data publication is supplement to. The model data is provided as text files (.csv extension) and Matlab-formatted files (.mat extension). For text files, there is one file per year (file name labeled with the corresponding year). For the Matlab format, there is only one Matlab file that contains all years as separate variables (variable name labeled with the corresponding year). Each yearly file/variable corresponds to a matrix: the rows represent local time/longitude bins and the columns represent days of year.
The local time/longitude bins (rows) always sum up to 432 (12 local time intervals and 36 longitude intervals). The day of year (columns) always starts in January 1st and ends in December 31st, leading to a total of 365 or 366. The PCEEJ model values of 13 years from 2003 to 2010 and from 2014 to 2018 are provided. The PCEEJ basis functions (principal components) are provided in the text and Matlab files labeled as ‘PC_Functions’. The ‘PC_Functions’ data is given as a 432x10 matrix, in which 432 stands for the aforementioned local time/longitude bins and 10 represents the 10 principal components used to obtain the PCEEJ model (in ascending order). Two additional auxiliary indices, namely ‘lt_index’ and ‘lon_index’ are also contained as text and Matlab files. These indices represent the corresponding local time and longitude values of each row of the PCEEJ yearly files and ‘PC_Functions’ files.
The data set contains hourly mean values (HMV) of the horizontal magnetic field component H as measured at the geomagnetic observatory Huancayo for 1935 to 1985. Huancayo (IAGA code HUA) is located close to the magnetic equator and is operated by Instituto Geofisico del Peru.
The HMVs were taken from the World Data Centre Kyoto (WDC Kyoto) and existing data gaps (in total some 19 years from the 1960ies, 1970ies and 1980ies) were filled in by typing handwritten records of the HMV at GFZ. These handwritten records were monthly tables that were received as digital images from geomagnetic observatory Huancayo or that were received as microfilms from World Data Centre Boulder, Colorado. We also produced digital images of these microfilms. The values from the WDC Kyoto are definitive values; the monthly tables presumably also contain definitive values.
Corrections to HUA HMVs from WDC Kyoto: There is a known error in the time stamping of the HUA HMVs prior to 1948 (before 1948 the data was reported in local time, rather than universal time). This error is corrected in the present dataset. Also, an attempt was made to correct for a jump in the HMV time series at this time. For further corrections, see Matzka et al, 2017.
Please note that a dataset based on the data provided here will be submitted to the WDC Kyoto at a later stage and might undergo further modifications.
The data file is in ASCII format and contains blank-separated first the year (YYYY), the month (MM), the day (DD) followed by the 24 HMVs of H (format HHHHH) in nanotesla (nT), starting with the HMV for 00 to 01 universal time.Geomagnetic observatories are described in e.g. Jankowski and Sucksdorf (1996).
This dataset comprises preliminary minute means of the XYZ (X=geographic north, Y=geographic east, Z=downward) magnetic field components measured at the geomagnetic observatory Tatuoca (IAGA code TTB) for the period June 1st, 2008 to December 31st, 2017. TTB is located in northern Brazil and operates under the administration of Observatório Nacional (ON) since 1957. Since 2015 it is operated in cooperation between ON and GFZ.Since the early years of the 2000 decade, the magnetic equator is close to the observatory TTB.The variations from June 1st 2008 until November 19th, 2015 were recorded by a LEMI-417M fluxgate magnetometer (sampling rate during most of this period was 1 sec, but occasionally 0.25 or 6 sec). From November 20th, 2015 onwards, a DTU FGE fluxgate magnetometer (1 sec sampling) provided the variations. From late October 2016, the total field F was measured with a Gemsys overhauser absolute scalar magnetometer with 1 sec sampling.This is a processed and calibrated dataset. Inconsistencies like spikes and data jumps were corrected. The maximum admitted noise level in this dataset is 1 nT peak to peak in the underlying 1 sec data. Periods of recurrent noise exceeding this criterion were systematically deleted from the records. For data calibration, the baseline was constructed by means of absolute measurements of the geomagnetic field and applied to the variation data.The data files are provided in the IAGA-2002 format (https://www.ngdc.noaa.gov/IAGA/vdat/IAGA2002/iaga2002format.html) as daily files for 1-minute means. Following the IAGA2002-format, the filename consists of the IAGA-code, the year (YYYY), the month (MM), the day (DD), the letter p for preliminary, the letters min for 1-minute data, and the file extension min again for 1-minute data. The first 16 lines in each file are a IAGA2002-typical header, then comes, blank separated, the date (YYYY-MM-DD), time (hh:mm:ss.sss in UTC), day of year (DOY), the X component (XXXXX.XX in nT), the Y-component (YYYYY.YY in nT), the Z-component (ZZZZZ.ZZ in nT) and F (FFFFF.FF in nT).Please note that a dataset based on the data provided here will be submitted to the World Data Centre for Geomagnetism (WDC Edinburgh) at a later stage and might undergo further modifications.Geomagnetic observatories in general are described in e.g. Jankowski and Sucksdorff (1996), Matzka et al. (2010). GFZ observatories and observatory cooperations are described in Matzka (2016). The Geomagnetic Observatory Tatuoca (TTB) is described in Moschhauser et al. (2017).