TY - JOUR

T1 - Measurements and modeling of cosmic noise absorption changes due to radio heating of the D region ionosphere

AU - Senior, A.

AU - Rietveld, M.T.

AU - Honary, F.

AU - Singer, W.

AU - Kosch, M.J.

N1 - Copyright (2011) American Geophysical Union. Further reproduction or electronic distribution is not permitted.

PY - 2011/4/14

Y1 - 2011/4/14

N2 - 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.

AB - 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.

KW - riometer

KW - eiscat

KW - heating DCS-publications-id

KW - art-1026

KW - DCS-publications-credits

KW - aries

KW - iono-fa

KW - iris

KW - DCS-publications-personnel-id

KW - 51

KW - 5

KW - 7

U2 - 10.1029/2010JA016189

DO - 10.1029/2010JA016189

M3 - Journal article

VL - 116

SP - 1

EP - 10

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - A04310

ER -