A topside investigation over a mid-latitude digisonde station in Cyprus. Issue 2 (15th January 2021)

• Record Type: Journal Article
• Authors: Singh, Arun Kumar; Haralambous, Haris; Oikonomou, Christina; Leontiou, Theodoros
• Is Part Of: Advances in space research. Volume 67:Issue 2(2021)
• Page Start: 739
• Page End: 748
• Publication Date: 2021-01-15
• Subjects: Topside ionosphere -- IRI-2016 model -- Electron density profile -- COSMIC/FORMOSAT-3 -- European Space Agency (ESA) Swarm satellite; Space sciences -- Periodicals; Astronautics -- Periodicals; Geophysics -- Periodicals; 500.505
• DOI: 10.1016/j.asr.2020.10.009
• Languages: English
• ISSNs: 0273-1177

Abstract

Highlights: Comparison of Swarm observations with Digisonde and IRI estimations. Comparison of COSMIC RO observations, Digisonde and IRI estimations. Comparison of COSMIC, Digisonde and IRI Ne profile for the matched peak. Abstract: We examine the systematic differences between topside electron density measurements recorded by different techniques over the low-middle latitude operating European station in Nicosia, Cyprus (geographical coordinates: 35.14 o N, 33.2 o E), (magnetic coordinates 31.86 o N, 111.83 o E). These techniques include space-based in-situ data by Langmuir probes on board. European Space Agency (ESA) Swarm satellites, radio occultation measurements on board low Earth orbit (LEO) satellites from the COSMIC/FORMOSAT-3 mission and ground-based extrapolated topside electron density profiles from manually scaled ionograms. The measurements are also compared with International Reference Ionosphere Model (IRI-2016) topside estimations and IRI-corrected NeQuick topside formulation (method proposed by Pezzopane and Pignalberi (2019)). The comparison of Swarm and COSMIC observations with digisonde and IRI estimations verifies that in the majority of cases digisonde underestimates while IRI overestimates Swarm observations but in general, IRI provides a better topside representation than the digisonde. For COSMIC and digisonde profiles matched at the F layer peak the digisonde systematically underestimates topside COSMIC electron density values and the relative difference between COSMIC and digisonde increases with altitude (above hm F2), while IRI overestimates the topside COSMIC electron density but after a certain altitude (~150 km above hm F2) this overestimation starts to decrease with altitude. The IRI-corrected NeQuick underestimates the majority of topside COSMIC electron density profiles and relative difference is lower up to approximately 100 km (above the hm F2) and then it increases. The overall performance of IRI-corrected NeQuick improves with respect to IRI and digisonde.