Critical Issues in Ionospheric Data Quality and Implications for Scientific Studies

Abstract

Ionospheric data are valuable records of the behavior of the ionosphere, solar activity, and the entire Sun-Earth system. The data are critical for both societally important services and scientific investigations of upper atmospheric variability. This work investigates some of the difficulties and pitfalls in maintaining long-term records of geophysical measurements. This investigation focuses on the ionospheric parameters contained in the historical data sets within the National Oceanic and Atmospheric Administration National Geophysical Data Center and Space Physics Interactive Data Resource databases. These archives include data from approximately 100 ionosonde stations worldwide, beginning in the early 1940s. Our study focuses on the quality and consistency of ionosonde data accessible via the primary Space Physics Interactive Data Resource node located within the National Oceanic and Atmospheric Administration National Geophysical Data Center and the World Data Center for Solar-Terrestrial Physics located in Boulder, Colorado. We find that, although the Space Physics Interactive Data Resource archives contained an impressive amount of high-quality data, specific problems existed involving missing and noncontiguous data sets, long-term variations or changes in methodologies and analysis procedures used, and incomplete documentation. The important lessons learned from this investigation are that the data incorporated into an archive must have clear traceability back to the primary source, including scientific validation by the contributors, and that the historical records must have associated metadata that describe relevant nuances in the observations. Although this report only focuses on historical ionosonde data in National Oceanic and Atmospheric Administration databases, we feel that these findings have general applicability to environmental scientists interested in using long-term geophysical data sets for climate and global change research.

ARTIST Ionogram Autoscaling Confidence Scores: Best Practices

“…Ionosondes provide one of the longest-running and most reliable measurements of the ionosphere [1]. By scanning across a range of frequencies in the HF band and measuring the echo time of signals reflected from the ionosphere, they are capable of producing ionograms.…”

Assessment of Global Ionospheric Maps Performance by Means of Ionosonde Data

“…A complimentary assessment to benefit the quality indicators of GIM's accuracy would be the incorporation of ionosonde measurements as a reference to specify the "true" ionosphere. The electron density peak in the F 2 layer (N m F 2 ) is commonly measured by ionosondes in terms of the associated critical frequency (foF 2 ), which is specially trustable when they are directly provided from manually calibrated ionosonde datasets [16]. Some studies related to the estimation of foF 2 can be found in works such as Altinay et al [17] and Pietrella et al [18].…”

The Early Results and Validation of FORMOSAT‐7/COSMIC‐2 Space Weather Products: Global Ionospheric Specification and Ne‐Aided Abel Electron Density Profile

“…Digisonde observations (Reinisch et al, 2009) over eight selected digisonde stations (AS00Q, GR13L, GU513, JI91J, LL721, LM42B, MHJ45, and SMK29 in Figure 5) located at low latitudes and midlatitudes during daytime from 14 September to 16 October 2019 are used to derive N m F 2 and h m F 2 ( F ‐peak altitude) (Reinisch & Galkin, 2011). Note that the N m F 2 and h m F 2 are acquired by manually scaling the ionograms to mitigate possible errors due to autoscaling (e.g., Araujo‐Pradere et al, 2019). In this study, a total of 1,465 digisonde observations is used to validate the peak density and altitude information from GIS.…”