High‐latitude Joule heating response to IMF inputs

McHarg, M. G.; Chun, F. K.; Knipp, D. J.; Lu, G.; Emery, B. A.; Ridley, A. J.

doi:10.1029/2004ja010949

Cited by 55 publications

(63 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The widely accepted paradigm is documented in papers by Weimer (2005), Cosgrove et al (2014), McHarg et al (2005, and others, in which the auroral zones and cusp dominate highlatitude energy input. The main reason for the discrepancy between our results and previous work lies in the way the data have been treated.…”

Section: Discussionmentioning

confidence: 99%

Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

Huang

et al. 2016

J. Space Weather Space Clim.

View full text Add to dashboard Cite

During magnetic storms, there is a strong response in the ionosphere and thermosphere which occurs at polar latitudes. Energy input in the form of Poynting flux and energetic particle precipitation, and energy output in the form of heated ions and neutrals have been detected at different altitudes and all local times. We have analyzed a number of storms, using satellite data from the Defense Meteorological Satellite Program (DMSP), the Gravity Recovery and Climate Experiment (GRACE), Gravity field and steady-state Ocean Circulation Explorer (GOCE), and Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission. Poynting flux measured by instruments on four DMSP spacecraft during storms which occurred in 2011-2012 was observed in both hemispheres to peak at both auroral and polar latitudes. By contrast, the measured ion temperatures at DMSP and maxima in neutral density at GOCE and GRACE altitudes maximize in the polar region most frequently with little evidence of Joule heating at auroral latitudes at these spacecraft orbital locations.

show abstract

Section: Discussionmentioning

confidence: 99%

Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

Huang

et al. 2016

J. Space Weather Space Clim.

View full text Add to dashboard Cite

show abstract

“…Tsurutani et al (2006b) proposed that HILD-CAA events cause high-latitude heating and corresponding disturbance dynamo effects which in turn affect high-latitude VTEC intensities. High-latitude thermospheric heating in response to different polarity of IMF Bz has been extensively studied by McHarg et al (2005). They concluded that hemispherically integrated Joule heating increases dramatically in the post-midnight sector of the auroral zone during southward IMF intervals.…”

Section: Discussionmentioning

confidence: 99%

Variability of ionospheric TEC during solar and geomagnetic minima (2008 and 2009): external high speed stream drivers

et al. 2013

View full text Add to dashboard Cite

We study solar wind–ionosphere coupling through the late declining phase/solar minimum and geomagnetic minimum phases during the last solar cycle (SC23) – 2008 and 2009. This interval was characterized by sequences of high-speed solar wind streams (HSSs). The concomitant geomagnetic response was moderate geomagnetic storms and high-intensity, long-duration continuous auroral activity (HILDCAA) events. The JPL Global Ionospheric Map (GIM) software and the GPS total electron content (TEC) database were used to calculate the vertical TEC (VTEC) and estimate daily averaged values in separate latitude and local time ranges. Our results show distinct low- and mid-latitude VTEC responses to HSSs during this interval, with the low-latitude daytime daily averaged values increasing by up to 33 TECU (annual average of ~20 TECU) near local noon (12:00 to 14:00 LT) in 2008. In 2009 during the minimum geomagnetic activity (MGA) interval, the response to HSSs was a maximum of ~30 TECU increases with a slightly lower average value than in 2008. There was a weak nighttime ionospheric response to the HSSs. A well-studied solar cycle declining phase interval, 10–22 October 2003, was analyzed for comparative purposes, with daytime low-latitude VTEC peak values of up to ~58 TECU (event average of ~55 TECU). The ionospheric VTEC changes during 2008–2009 were similar but ~60% less intense on average. There is an evidence of correlations of filtered daily averaged VTEC data with Ap index and solar wind speed. We use the infrared NO and CO2 emission data obtained with SABER on TIMED as a proxy for the radiation balance of the thermosphere. It is shown that infrared emissions increase during HSS events possibly due to increased energy input into the auroral region associated with HILDCAAs. The 2008–2009 HSS intervals were ~85% less intense than the 2003 early declining phase event, with annual averages of daily infrared NO emission power of ~ 3.3 × 1010 W and 2.7 × 1010 W in 2008 and 2009, respectively. The roles of disturbance dynamos caused by high-latitude winds (due to particle precipitation and Joule heating in the auroral zones) and of prompt penetrating electric fields (PPEFs) in the solar wind–ionosphere coupling during these intervals are discussed. A correlation between geoeffective interplanetary electric field components and HSS intervals is shown. Both PPEF and disturbance dynamo mechanisms could play important roles in solar wind–ionosphere coupling during prolonged (up to days) external driving within HILDCAA intervals

show abstract

“…With moderately southward IMF, the total ionospheric heating in both hemispheres is several hundred gigawatts (GW) [Chun et al, 1999[Chun et al, , 2002McHarg et al, 2005], and during major geomagnetic storm periods the heating may exceed 1000 GW [Lu et al, 1998]. The result is that the thermosphere expands upward, creating additional drag on objects in low Earth orbit (LEO).…”

Section: Introductionmentioning

confidence: 99%

Predicting global average thermospheric temperature changes resulting from auroral heating

et al. 2011

View full text Add to dashboard Cite

[1] The total Poynting flux flowing into both polar hemispheres as a function of time, computed with an empirical model, is compared with measurements of neutral densities in the thermosphere at two altitudes obtained from accelerometers on the CHAMP and GRACE satellites. The Jacchia-Bowman 2008 empirical thermospheric density model (JB2008) is used to facilitate the comparison. This model calculates a background level for the "global nighttime minimum exospheric temperature," T c , from solar indices. Corrections to this background level due to auroral heating, DT c , are presently computed from the Dst index. A proxy measurement of this temperature difference, DT c , is obtained by matching the CHAMP and GRACE density measurements with the JB2008 model. Through the use of a differential equation, the DT c correction can be predicted from IMF values. The resulting calculations correlate very well with the orbit-averaged measurements of DT c , and correlate better than the values derived from Dst. Results indicate that the thermosphere cools faster following time periods with greater ionospheric heating. The enhanced cooling is likely due to nitric oxide (NO) that is produced at a higher rate in proportion to the ionospheric heating, and this effect is simulated in the differential equations. As the DT c temperature correction from this model can be used as a direct substitute for the Dst-derived correction that is now used in JB200, it could be possible to predict DT c with greater accuracy and lead time.

show abstract

High‐latitude Joule heating response to IMF inputs

Cited by 55 publications

References 29 publications

Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

Variability of ionospheric TEC during solar and geomagnetic minima (2008 and 2009): external high speed stream drivers

Predicting global average thermospheric temperature changes resulting from auroral heating

Contact Info

Product

Resources

About