Critical issues in ionospheric data quality and implications for scientific studies

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.Peer ReviewedPostprint (published version

Comparing daytime, equatorial <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities and TOPEX/TEC observations associated with the 4-cell, non-migrating tidal structure

We investigate the seasonal and longitude dependence of the daytime, vertical E&times;B drift velocities, on a day-to-day basis, using a recently-developed technique for inferring realistic E&times;B drifts from ground-based magnetometer observations. We have chosen only quiet days, Ap&lt;10, from January 2001 through December 2002, so that the main contribution to the variability is due to the variability in the tidal forcing from below. In order to study the longitude dependence in daytime E&times;B drift velocities, we use appropriately-placed magnetometers in the Peruvian, Philippine, Indonesian and Indian longitude sectors. Since we are particularly interested in quantifying the E&times;B drift velocities associated with the 4-cell, non-migrating tidal structure, we compare the seasonal and longitude E&times;B drift structure with TOPEX satellite observations of Total Electron Content (TEC). We outline a plan to establish the magnitude of the longitude gradients that exist in the daytime, vertical E&times;B drift velocities at the boundaries of the observed 4-cell patterns and to theoretically identify the physical mechanisms that account for these sharp gradients. The paper demonstrates that sharp gradients in E&times;B drift velocities exist at one of the 4-cell boundaries and outlines how the C/NOFS IVM and VEFI sensor observations could be used to establish the E&times;B drift longitude gradients at the boundaries of each of the 4 cells. In addition, the paper identifies one of the theoretical, atmosphere/ionosphere models that could be employed to identify the physical mechanisms that might explain these observations

Comparing daytime, equatorial <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities and TOPEX/TEC observations associated with the 4-cell, non-migrating tidal structure

We investigate the seasonal and longitude dependence of the daytime, vertical <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities, on a day-to-day basis, using a recently-developed technique for inferring realistic <I><B>E</B></I>&times;<I><B>B</B></I> drifts from ground-based magnetometer observations. We have chosen only quiet days, <I>A_p</I>&lt;10, from January 2001 through December 2002, so that the main contribution to the variability is due to the variability in the tidal forcing from below. In order to study the longitude dependence in daytime <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities, we use appropriately-placed magnetometers in the Peruvian, Philippine, Indonesian and Indian longitude sectors. Since we are particularly interested in quantifying the <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities associated with the 4-cell, non-migrating tidal structure, we compare the seasonal and longitude <I><B>E</B></I>&times;<I><B>B</B></I> drift structure with TOPEX satellite observations of Total Electron Content (TEC). We outline a plan to establish the magnitude of the longitude gradients that exist in the daytime, vertical <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities at the boundaries of the observed 4-cell patterns and to theoretically identify the physical mechanisms that account for these sharp gradients. The paper demonstrates that sharp gradients in <I><B>E</B></I>&times;<I><B>B</B></I> drift velocities exist at one of the 4-cell boundaries and outlines how the C/NOFS IVM and VEFI sensor observations could be used to establish the <I><B>E</B></I>&times;<I><B>B</B></I> drift longitude gradients at the boundaries of each of the 4 cells. In addition, the paper identifies one of the theoretical, atmosphere/ionosphere models that could be employed to identify the physical mechanisms that might explain these observations

A model of a perturbed ionosphere using the auroral power as the input

Este trabajo presenta un modelo semiempírico basado en la teoría desarrollada por Fuller-Rowell et al (1996). El modelo predice cambios en el cociente entre los valores observados y las medianas mensuales de la frecuencia crítica de la capa F2 ionosférica Ö (= foF2obs/foF2mm) durante condiciones perturbadas y requiere la historia temporal de las 30 horas anteriores del índice de potencia auroral (o del índice ap) del satélite TIROS/NOAA, afectado por un filtro. Encontramos que las dependencias estacionales, latitudinales y del tiempo local de la ionosfera perturbada están de acuerdo con el modelo. doi: https://doi.org/10.22201/igeof.00167169p.2000.39.1.29