Coordinated incoherent scatter radar study of the January 1997 storm

Buonsanto, M. J.; González, S. A.; Lu, G.; Reinisch, B. W.; Thayer, J. P.

doi:10.1029/1999ja900358

Cited by 38 publications

(39 citation statements)

References 53 publications

(12 reference statements)

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“…Typical maximum energy fluxes are in the range 10 to 20 mW/m 2 (Thayer, 1998b(Thayer, , 2000Lu et al, 1996;Buonsanto et al, 1999;Slinker et al, 1999). For this event however, the maximum electromagnetic energy flux was 50 mW/m 2 , considerably higher than typical maxima inferred from radars and assimilation techniques.…”

Section: Discussion and Summarymentioning

confidence: 93%

“…First, the 57 GW total energy deposition is higher than one would have expected. It is comparable to the average heating power at auroral latitudes of 84 GW from the EISCAT and SABRE radars (Kosch and Nielsen, 1995) and is also in the range of heating rates obtained by other techniques for non-storm time moderate activity which are typically 50 to 100 GW (e.g., Lu et al, 1996;Buonsanto et al, 1999;Slinker et al, 1999). Foster et al (1983) conducted a statistical analysis of AE-C satellite measurements, binning ion drift and particle precipitation as a function of K p .…”

Section: Discussion and Summarymentioning

confidence: 99%

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High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

et al. 2005

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Abstract. We present a case study of a prolonged interval of strongly northward orientation of the interplanetary magnetic field on 16 July 2000, 16:00-19:00 UT to characterize the energy exchange between the magnetosphere and ionosphere for conditions associated with minimum solar windmagnetosphere coupling. With reconnection occurring tailward of the cusp under northward IMF conditions, the reconnection dynamo should be separated from the viscous dynamo, presumably driven by the Kelvin-Helmholtz (KH) instability. Thus, these conditions are also ideal for evaluating the contribution of a viscous interaction to the coupling process. We derive the two-dimensional distribution of the Poynting vector radial component in the northern sunlit polar ionosphere from magnetic field observations by the constellation of Iridium satellites together with drift meter and magnetometer observations from the Defense Meteorological Satellite Program (DMSP) F13 and F15 satellites. The electromagnetic energy flux is then compared with the particle energy flux obtained from auroral images taken by the far-ultraviolet (FUV) instrument on the Imager for Magnetopause to Aurora Global Exploration (IMAGE) spacecraft. The electromagnetic energy input to the ionosphere of 51 GW calculated from the Iridium/DMSP observations is eight times larger than the 6 GW due to particle precipitation all poleward of 78 • MLAT. This result indicates that the energy transport is significant, particularly as it is concentrated in a small region near the magnetic pole, even under conditions traditionally considered to be quiet and is dominated by the electromagnetic flux. We estimate the contributions of the high and mid-latitude dynamos to both the Birkeland currents and electric potentials finding that highlatitude reconnection accounts for 0.8 MA and 45 kV while we attribute <0.2 MA and ∼5 kV to an interaction at lower latitudes having the sense of a viscous interaction. Given that these conditions are ideal for the occurrence of the KH instability at the magnetopause and hence the viscous interaction, Correspondence to: H. Korth (haje.korth@jhuapl.edu) this result suggests that the viscous interaction is a small contributor to coupling solar wind energy to the magnetosphereionosphere system.

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Section: Discussion and Summarymentioning

confidence: 93%

Section: Discussion and Summarymentioning

confidence: 99%

High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

et al. 2005

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“…The data from the incoherent scatter radar network and the Ramey Digisonde have been presented and discussed by Buonsanto et al [1999], who made comparisons with the calculations of the TIEGCM which has been described by Richmond et al [1992].…”

Section: Datamentioning

confidence: 99%

On the relative importance of convection and temperature to the behavior of the ionosphere in North America during January 6–12, 1997

Richards

Buonsanto²,

Reinisch³

et al. 2000

J. Geophys. Res.

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Abstract. This paper is primarily concerned with the causes of the large density and temperature enhancements that are often observed during magnetically quiet periods on winter nights at midlatitudes in the North American sector. Measurements from a network of Digisondes and an incoherent scatter radar are compared with the field line interhemispheric plasma (FLIP) model for January 6-12, 1997, in order to examine the temporal evolution and geographical extent of the enhancements in eastern North America. Postsunset measurements at Millstone Hill show high electron temperatures accompanied by rapid density decay until midnight followed by a rapid temperature decay accompanied by a pronounced density enhancement in the early morning hours. The FLIP model reproduces the nighttime density enhancement well, provided the model is constrained to follow the topside electron temperature and also that the overlying plasmaspheric flux tube is full. The dramatic reduction in plasmaspheric heat flux near midnight results in a sharp decrease in ionospheric temperature, inducing a large downward flow of plasmaspheric ions which creates the nighttime enhancement in ionospheric density. We find that the nighttime plasmaspheric heat flux variation drives the nighttime ionospheric density variation, which is opposite to conclusions in previously published work. Although the plasmaspheric heat flux variation can explain the ionospheric density variation, the reasons for this heat flux variation are not understood. Convection of plasma from higher magnetic latitudes is now included in the FLIP model but is not needed to produce the observed nighttime density maximum. We have found that the fraction of light ions in the topside ionosphere at 500 km altitude in the model is very close to that obtained from chemical equilibrium and agrees well with the measured fraction. The model generally reproduces the daytime electron density very well at all stations except Bermuda, where the difference is as much as 50%.

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“…Travelling atmospheric disturbances, launched by high-latitude heating events, could cause fluctuations in hmF2 by raising the height of the layer (e.g. Buonsanto et al, 1999a). The exact contributions from these mechanisms, as well as from changes in the atomic oxygen density (i.e.…”

Section: Latitudinal Variations In Ionospheric Parametersmentioning

confidence: 99%

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

et al. 2005

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Abstract. This paper describes the ionospheric response to a geomagnetic storm beginning on 17 April 2002. We present the measurements of ionospheric parameters in the F-region obtained by the network of eight incoherent scatter radars. The main effects of this storm include a deep decrease in the electron density observed at high and middle latitudes in the pre-noon sector, and a minor enhancement in the density observed in the daytime sector at middle latitudes. Extreme plasma heating (>1000−3000 K) is observed at high latitudes, subsiding to 200-300 K at subauroral latitudes. The western hemisphere radar chain observed the prompt penetration of the electric field from auroral to equatorial latitudes, as well as the daytime enhancement of plasma drift parallel to the magnetic field line, which is related to the enhancement in the equatorward winds. We suggest that in the first several hours after the storm onset, a negative phase above Millstone Hill (pre-noon sector) results from counteracting processes -penetration electric field, meridional wind, and electrodynamic heating, with electrodynamic heating being the dominant mechanism. At the lower latitude in the prenoon sector (Arecibo and Jicamarca), the penetration electric field becomes more important, leading to a negative storm phase over Arecibo. In contrast, in the afternoon sector at mid-latitudes (Kharkov, Irkutsk), effects of penetration electric field and meridional wind do not counteract, but add up, leading to a small (∼15%), positive storm phase over these locations. As the storm develops, Millstone Hill and Irkutsk mid-latitude radars observe further depletion of electron density due to the changes in the neutral composition.

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Coordinated incoherent scatter radar study of the January 1997 storm

Cited by 38 publications

References 53 publications

High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

On the relative importance of convection and temperature to the behavior of the ionosphere in North America during January 6–12, 1997

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

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