Electric field variability associated with the Millstone Hill electric field model

Codrescu, M.; Fuller‐Rowell, T. J.; Foster, J. C.; Holt, J. M.; Cariglia, S. J.

doi:10.1029/1999ja900463

Cited by 95 publications

(152 citation statements)

References 14 publications

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“…At first glance, this might seem a surprising result and inconsistent with the results of Codrescu et al (2000). But we have used a different analysis approach.…”

Section: Discussionmentioning

confidence: 99%

“…First, we estimate typical variations of electric fields using data collected by the European Incoherent Scatter (EISCAT) radar (Rishbeth and Williams, 1984). The results are compared with those of Codrescu et al (2000). We then use these findings to modify the input parameters to the coupled thermosphere-ionosphere-plasmasphere model known as CTIP to determine both the thermospheric and ionospheric consequences of using a more realistic electric field description.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, we expand upon the general approach of Codrescu et al (1995Codrescu et al ( , 2000 by further examining some of the consequences of assuming that the electric field is an hourly-average. First, we estimate typical variations of electric fields using data collected by the European Incoherent Scatter (EISCAT) radar (Rishbeth and Williams, 1984).…”

Section: Introductionmentioning

confidence: 99%

“…This showed that the Joule heating can be underestimated by 30-230%, depending exactly upon the assumptions made in the model calculations. Codrescu et al (2000) have extended the analysis to provide variations in electric fields as a function of latitude, time and geomagnetic activity. They show that plasma velocity and its standard variation demonstrate considerable variation in space and MLT for both disturbed and moderate conditions.…”

Section: Introductionmentioning

confidence: 99%

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The variability of Joule heating, and its effects on the ionosphere and thermosphere

et al. 2001

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Abstract.A considerable fraction of the solar wind energy that crosses the magnetopause ends up in the high-latitude thermosphere-ionosphere system as a result of Joule heating, the consequences of which are very significant and global in nature. Often Joule heating calculations use hourly averages of the electric field, rather than the time-varying electric field. This leads to an underestimation of the heating. In this paper, we determine the magnitude of the underestimation of Joule heating by analysing electric field data from the EISCAT Incoherent Scatter Radar, situated at the 67 • E magnetic latitude. We find that the underestimation, using hourly-averaged electric field values, is normally ∼20%, with an upper value of about 65%. We find that these values are insensitive to changes in solar flux, magnetic activity and magnetic local time, implying that the electric field fluctuations are linear related to the amplitude of the electric field. Assuming that these changes are representative of the entire auroral oval, we then use a coupled ionosphere-thermosphere model to calculate the local changes these underestimations in the heating rate cause to the neutral temperature, mean molecular mass and meridional wind. The changes in each parameter are of the order of a few percent but they result in a reduction in the peak F-region concentration of ∼20% in the summer hemisphere at high latitudes, and about half of this level in the winter hemisphere. We suggest that these calculations could be used to add corrections to modelled values of Joule heating.

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“…At first glance, this might seem a surprising result and inconsistent with the results of Codrescu et al (2000). But we have used a different analysis approach.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The variability of Joule heating, and its effects on the ionosphere and thermosphere

et al. 2001

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“…However, they found no relationship with magnetic activity, that is, the gravity wave amplitude and occurrence rate did not depend on Kp. However, Codrescu et al (2000) have shown that small-scale electric field fluctuations can lead to Joule heating effects, even at low Kp. Alternatively, the in situ generation of gravity waves discussed by Vadas et al (2003) and Vadas and Liu (2009) may be the source.…”

Section: Introductionmentioning

confidence: 99%

On the origin of mesoscale TIDs at midlatitudes

Kelley

2011

Ann. Geophys.

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Abstract.A recent breakthrough experiment by Ogawa et al. (2009) showed that Mesoscale Traveling Ionospheric Disturbances (MSTIDs), a common phenomenon at midlatitudes, originate in the auroral zone as gravity waves. Curiously, however, the latter do not seem to be related to magnetic activity. These atmospheric waves are common at high latitudes , and we argue here that, as they propagate to lower latitudes, Joule damping reduces the gravity wave spectrum to waves suffering the weakest damping. The direction of weakest damping corresponds to the direction predicted by the Perkins instability (Perkins, 1973) for nighttime MSTIDs.

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Empirical model of Poynting flux derived from FAST data and a cusp signature

et al. 2014

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[1] Empirical models of the Poynting flux and particle kinetic energy flux, associated with auroral processes, have been constructed using data from the FAST satellite and are available online. The models output flux maps as a function of several geophysical parameters: (1) clock angle of the interplanetary magnetic field (IMF), (2) magnitude of the IMF in the GSM y-z plane, (3) solar wind speed, (4) solar wind number density, (5) magnetic dipole tilt angle, and (6) the AL index (optional for Poynting flux). The choice of parameters is motivated by the Weimer potential model. Because the Poynting flux distribution has a heavy tail, care must be taken in applying the model to events that may be uncommon, and the model output includes a measure of quality based on the density of FAST orbits in the parameter space. The models are constructed by fitting the data to a sum of empirical orthogonal functions (EOFs), with coefficients modeled by quadratic equations in the geophysical parameters. The EOFs are constructed from the same data set using singular value decomposition, along with a smoothing/interpolation algorithm that minimizes curvature and incorporates uncertainty. Potential applications include specification of the auroral energy input for general circulation models. Basic findings from the model include verification of the importance of the auroral electrojets as features of auroral Poynting flux deposition and identification of the cusp as a third important feature. The cusp makes an important contribution to the overall energy budget when the IMF is north of˙90 ı .

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Electric field variability associated with the Millstone Hill electric field model

Cited by 95 publications

References 14 publications

The variability of Joule heating, and its effects on the ionosphere and thermosphere

The variability of Joule heating, and its effects on the ionosphere and thermosphere

On the origin of mesoscale TIDs at midlatitudes

Empirical model of Poynting flux derived from FAST data and a cusp signature

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