| 1. |
- Abbafati, Cristiana, et al.
(författare)
-
- 2020
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
- Gustavsson, B., Sergienko, T., Rietveld, M.T., Honary, F., Steen, A., Brandstrom, B.U., Leyser, T.B., Aruliah, A.L., Aso, T., Ejiri, M. and Marple, S.
(författare)
-
First Tomographic estimate of volume distribution of HF-pump enhanced airglow emission.
- 2001
-
Ingår i: Journal of Geophysical Research. ; 106:A12, s. 29105-29123
-
Tidskriftsartikel (refereegranskat)abstract
- This report presents the first estimates of the three-dimensional volume emission rate of enhanced O(D-1) 6300 Angstrom airglow caused by HF radio wave pumping in the ionosphere. Images of the excitation show how the initially speckled spatial structure o
|
|
| 3. |
- Gustavsson, B., et al.
(författare)
-
Electron gyroharmonic effects in ionization and electron acceleration during high-frequency pumping in the ionosphere
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:19, s. 195002-
-
Tidskriftsartikel (refereegranskat)abstract
- Optical emissions and incoherent scatter radar data obtained during high-frequency electromagnetic pumping of the ionospheric plasma from the ground give data on electron energization in an energy range from 2 to 100 eV. Optical emissions at 4278 angstrom from N-2(+) that require electrons with energies above the 18 eV ionization energy give the first images ever of pump-induced ionization of the thermosphere. The intensity at 4278 angstrom is asymmetric around the ionospheric electron gyroharmonic, being stronger above the gyroresonance. This contrasts with emissions at 6300 angstrom from O(D-1) and of electron temperature enhancements, which have minima at the gyroharmonic but have no apparent asymmetry. This direct evidence of pump-induced ionization contradicts previous indirect evidence, which indicated that ionization is most efficiently produced when the pump frequency was below the gyroharmonic.
|
|
| 4. |
- Leyser, T., Gustavsson, Brändström, B.U.E., Steen, Å., Honary, F., Rietveld, M., Aso, T. and Ejiri, M.
(författare)
-
Simultaneous measurements of high-frequency pump-enhanced airglow and ionospheric temperatures at auroral latitudes.
- 2000
-
Ingår i: Adv. Polar Upper Atmos. ; 14, s. 2002-1
-
Tidskriftsartikel (refereegranskat)
|
|
| 5. |
- Brandstrom, BUE, et al.
(författare)
-
Unambiguous evidence of HF pump-enhanced airglow at auroral latitudes
- 1999
-
Ingår i: GEOPHYSICAL RESEARCH LETTERS. - : AMER GEOPHYSICAL UNION. - 0094-8276. ; 26:23, s. 3561-3564
-
Tidskriftsartikel (refereegranskat)abstract
- Simultaneous observations by up to three low-light imaging stations belonging to the Auroral Large Imaging System (ALIS) have provided the first strong evidence of high-frequency (HF) pump-enhanced airglow at auroral latitudes. The airglow was enhanced by
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Ogawa, Y., et al.
(författare)
-
On the source of the polar wind in the polar topside ionosphere : First results from the EISCAT Svalbard radar
- 2009
-
Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 36:24, s. L24103-
-
Tidskriftsartikel (refereegranskat)abstract
- We present quantitative radar observations of both hydrogen ion (H+) and oxygen ion (O+) upflow in the topside polar ionosphere using measurements that were recently carried out with the EISCAT Svalbard Radar and the Reimei satellite. H+ upflow was clearly observed equatorward of the cusp above 500 km altitude. Within the cusp the H+ density was very low, and the upflow was dominated by O+ ions, but on closed field lines the H+ became the larger contributor to the upward flux above about 550 km. The total flux seemed to be conserved, and so below 550 km altitude O+ (with a small upward velocity of similar to 50 m s(-1)) appeared to determine the upward flux which was then maintained by H+! in the topside ionosphere. We also found that the H+ density in the topside polar ionosphere was several times higher than current predictions of ionospheric models like IRI2001.
|
|
