We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK


93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Measurements and modeling of cosmic noise absor...
View graph of relations

« Back

Measurements and modeling of cosmic noise absorption changes due to radio heating of the D region ionosphere

Research output: Contribution to journalJournal article


Journal publication date14/04/2011
JournalJournal of Geophysical Research
Number of pages10
Original languageEnglish


Powerful high‐frequency radio waves can heat the electrons in the D region of the ionosphere. This heating increases the electron‐neutral collision frequency which modifies the absorption of other radio waves propagating through the heated plasma. A high spatial resolution imaging riometer was used to observe changes in cosmic radio noise absorption (CNA) induced by heating from the European Incoherent Scatter (EISCAT) HF facility, and the results were compared to a theoretical model using observed electron densities as an input. The model is found to overestimate the observed effect by a factor close to 2, despite different background electron density profiles and heater powers. However, the model reproduced the spatial morphology of the change in CNA rather well, and the same absorption calculation used in the heating model also reproduced the changes in CNA due to electron precipitation in the absence of heating well. When the assumption of a perfectly conducting ground is replaced with a more realistic model in the calculation of the HF radiated power, the power is reduced to about 75% of its original value, and the model overestimate of the CNA change is reduced to a factor of about 1.3.

Bibliographic note

Copyright (2011) American Geophysical Union. Further reproduction or electronic distribution is not permitted.