thermospheric wind during a storm time large scale traveling ionospheric disturbance 1 a prominent large scale traveling ionospheric disturbance lstid was observed in japan during the major magnetic storm dst 358 nt of 31 march 2001 it was detected as enhancements of the 630 nm airglow and fof2 gps tec variations and a decrease in f layer virtual height at 1700 1900 ut 0200 0400 lt it moved equatorward with a speed of 600 m s the decrease in the f layer height was also detected by the mu radar at shigaraki thermospheric wind variations were observed by the mu radar through ion drift measurement and by a fabry perot interferometer fpi through a doppler shift of the 630 nm airglow line at shigaraki the wind data show a turn of the meridional wind from 94 m s equatorward to 44 m s poleward during the lstid indicating that an intense poleward wind in the thermosphere passed over shigaraki as an atmospheric gravity wave and caused the observed ionospheric features of the lstid intense poleward wind was also detected at mesospheric altitudes 95 100 km by the mu radar through meteor echoes and by the fpi through the 558 nm airglow with a delay of 2 hours from the thermospheric wind indicating downward phase progression of the wave generation of the observed poleward wind in the auroral zone was investigated using magnetic field data and auroral energy input estimated by the assimilative mapping of ionospheric electrodynamics amie technique we suggest that simple atmospheric heating and or the lorentz force in the auroral zone do not explain the observed poleward wind enhancement

no evidence for extreme long term warming in early pliocene sediments of the southern ocean abstract during the past 10 years there has been considerable debate with respect to the response of the antarctic ice sheets to early pliocene warmth interpretations generally fall into one of three categories 1 there was a major drawdown of the east antarctic ice sheet eais 2 drawdown of eais was relatively small 3 eais was largely unaffected by early pliocene warmth here this question is approached by using biogenic opal and carbonate in deep sea sediments as proxy for paleoceanographic change during the present day these measures are largely dictated by the position of the antarctic polar front apf with biogenic carbonate exhibiting an increase north of the apf and biogenic opal increasing to the south that the carbonate opal transition zone is a reliable feature in deep sea sediments is evidenced by the fact that it is recorded north of its present position during the last glacial maximum lgm and to the south of it during oxygen isotope stage 11 a warmer than present interglacial when these proxies are applied to southern ocean sediments high frequency glacial interglacial changes are seen in the pliocene and early pleistocene what appears to be a major glacial is recorded at about 4 5 myrs b p three short duration carbonate highs up to 18 suggesting a southward movement of apf occur at discrete intervals between about 4 6 4 8 myrs b p however these disappear or become reduced in amplitude toward the continent such data do not support any appreciable warming of surface waters near the antarctic continent neither does it support any claims of high circa 20 c sea level air temperatures over the eais it is concluded that there is no evidence for significant drawdown of eais during early pliocene warmth

f region behavior in the sed plume during a geomagnetic superstorm a case study 1 we report observations from the gps total electron content tec ionosonde and millstone hill incoherent scatter radar showing some interesting features of the height profile of the ionospheric electron density that occurred during a passage of a storm enhanced density sed plume during the geomagnetic superstorm on 20 november 2003 first the tec increases to about 6 58 times the quiet day value while the f peak plasma density nmf2 only enhances by a factor of 1 37 second the f2 layer peak height hmf2 is dramatically lifted from the quiet time altitude of 250 km to an unusual altitude of 577 km furthermore the topside chapman scale height ht is larger by a factor of 6 25 compared to the quiet time value as a result the electron density content with an chapman function above 700 km contributes about 59 to the total content during the sed event our analysis shows that during a passage of the sed plume the enhancement of tec is mainly attributed to the great increase of ht with a very high hmf2

earth s ion upflow associated with polar cap patches global and in situ observations we report simultaneous global monitoring of a patch of ionization and in situ observation of ion upflow at the center of the polar cap region during a geomagnetic storm our observations indicate strong fluxes of upwelling o ions originating from frictional heating produced by rapid antisunward flow of the plasma patch the statistical results from the crossings of the central polar cap region by defense meteorological satellite program f16 f18 from 2010 to 2013 confirm that the field aligned flow can turn upward when rapid antisunward flows appear with consequent significant frictional heating of the ions which overcomes the gravity effect we suggest that such rapidly moving patches can provide an important source of upwelling ions in a region where downward flows are usually expected these observations give new insight into the processes of ionosphere magnetosphere coupling

response of the equatorial ionosphere at dusk to penetration electric fields during intense magnetic storms 1 we investigate the response of the equatorial ionosphere at dusk to the intense magnetic storms of 30 october 2003 and 20 november 2003 different aspects of which have been widely studied by the community we present here a very complete set of space and ground based diagnostics that provide the vertical and latitudinal structures of the ionosphere within the south atlantic magnetic anomaly sama region and the contiguous parts of south america and africa we show that for both storms the dusk sector corresponding to the universal time ut interval between the fast decrease of the sym h index and minimum sym h value determines uniquely the longitude interval populated by equatorial plasma bubbles and depletions further we find that the ut of these storms is such that the ionospheric density perturbations occur in the sama region which are most extended in latitude and altitude compared with other regions of the globe in the dusk sector the eastward penetration electric field associated with rapid sym h decrease adds to the postsunset eastward e field because of the f region dynamo which may be specially enhanced in this longitude interval because of the increased zonal conductivity gradient caused by energetic particle precipitation this enhanced e field at dusk causes a rapid uplift of the ionosphere and sets off plasma instabilities to form bubbles or bite outs the decreased ion density seen in the defense meteorological satellite program dmsp in situ data at 840 km indicates that the ionospheric plasma has been lifted above the dmsp altitude and transported away from the region by diffusion along magnetic field lines plasma bubbles and bite outs impact satellite communication and navigation systems by introducing scintillations and steep density gradients this paper corroborates that intense magnetic storms follow the framework developed by su basu et al 2001 for moderate storms that specifies the longitude interval in which such disturbances are most likely to occur

middle and low latitude ionosphere response to 2015 st patrick s day geomagnetic storm this paper presents a study of the st patrick s day storm of 2015 with its ionospheric response at middle and low latitudes the effects of the storm in each longitudinal sector asian african american and pacific are characterized using global and regional electron content at the beginning of the storm one or two ionospheric positive storm effects are observed depending on the longitudinal zones after the main phase of the storm a strong decrease in ionization is observed at all longitudes lasting several days the american region exhibits the most remarkable increase in vertical total electron content vtec while in the asian sector the largest decrease in vtec is observed at low latitudes using spectral analysis we were able to separate the effects of the prompt penetration of the magnetospheric convection electric field ppef and of the disturbance dynamo electric field ddef on the basis of ground magnetic data concerning the ppef earth s magnetic field oscillations occur simultaneously in the asian african and american sectors during southward magnetization of the b z component of the interplanetary magnetic field concerning the ddef diurnal magnetic oscillations in the horizontal component h of the earth s magnetic field exhibit a behavior that is opposed to the regular one these diurnal oscillations are recognized to last several days in all longitudinal sectors the observational data obtained by all sensors used in the present paper can be interpreted on the basis of existing theoretical models

duskside enhancement of equatorial zonal electric field response to convection electric fields during the st patrick s day storm on 17 march 2015 the equatorial zonal electric field responses to prompt penetration of eastward convection electric fields ppef were compared at closely spaced longitudinal intervals at dusk to premidnight sectors during the intense geomagnetic storm of 17 march 2015 at dusk sector indian longitudes a rapid uplift of equatorial f layer to 550 km and development of intense equatorial plasma bubbles epbs were observed these epbs were found to extend up to 27 13 n and 25 98 s magnetic dip latitudes indicating their altitude development to 1670 km at apex in contrast at few degrees east in the premidnight sector thailand indonesian longitudes no significant height rise and or epb activity has been observed the eastward electric field perturbations due to ppef are greatly dominated at dusk sector despite the existence of background westward ionospheric disturbance dynamo idd fields whereas they were mostly counter balanced by the idd fields in the premidnight sector in situ observations from swarm a and swarm c and communication navigation outage forecasting system satellites detected a large plasma density depletion near indian equatorial region due to large electrodynamic uplift of f layer to higher than satellite altitudes further this large uplift is found to confine to a narrow longitudinal sector centered on sunset terminator this study brings out the significantly enhanced equatorial zonal electric field in response to ppef that is uniquely confined to dusk sector the responsible mechanisms are discussed in terms of unique electrodynamic conditions prevailing at dusk sector in the presence of convection electric fields associated with the onset of a substorm under southward interplanetary magnetic field bz

dmsp gps observations of intense ion upflow in the midnight polar ionosphere associated with the sed plume during a super geomagnetic storm 1 we report observations from the gps tec and dmsp f 15 satellite showing that a very strong upward field aligned fa plasma velocity and flux at f region heights in the auroral zone polar cap boundary during a passage of the polar tongue of ionization toi full of storm enhanced density sed materials occurred in the event of the super geomagnetic storm on nov 20 2003 the upward fa ion velocities in excess of 460 m s are obtained from observations of the dmsp f 15 satellite with enhancements of the plasma density caused by the toi fa ion fluxes are estimated to about 1 2 1014 ions m 2s 1 which are comparable to those observed by the ground based radar in the polar cusp therefore during the super geomagnetic storm a s sed can cause a toi plume at f region altitudes which leads to a strong upward ion flux reaching 1 2 orders of magnitude larger than that of the typical flux at midnight auroral zone polar cap boundary through estimations of the influence of those upflow ions associated with sed plumes on the development of the super storm our result suggests that the midnight auroral zone polar cap boundary becomes an important source to directly provide rich o to the ring current during super geomagnetic storms

observations from millstone hill during the geomagnetic disturbances of march and april 1990 the incoherent scatter radars at millstone hill operated continuously during the periods march 16 23 and april 6 12 1990 providing observations of large scale ionospheric structure and dynamics over a large portion of eastern north america major geomagnetic storms occurred during each of these periods with deep nighttime ionospheric troughs and large magnetospheric convection electric fields observed equatorward of millstone the millstone observations provide a comprehensive data set detailing storm induced ionospheric effects over a 35 span of latitude during both of these intervals at the latitude of millstone the ionospheric peak height hmf2 rose above 600 km in the trough on march 22 and 23 and reached 500 km at night on april 11 and 12 increased recombination apparently due to the strong electric fields the temperature dependent recombination rate coefficient and neutral composition changes greatly depleted the f2 region over a wide latitude range during the day on april 10 1990 this resulted in an ionosphere dominated by molecular ions with ionospheric peak heights below 200 km on this day a number of frictional heating events during the disturbed periods are seen from comparison of ion temperature and velocity measurements the most intense event took place near 1200 ut 0715 lmt on april 10 1990 when kp reached 8 at 0110 ut on march 21 line of sight ion velocities in excess of 500 m s 1 were observed at the extreme southern limit of the millstone steerable radar s field of view 40 apex magnetic latitude at an altitude of 700 km these could be due to penetration of magnetospheric electric fields or electric fields associated with ring current shielding in the storm time outer plasmasphere about an hour later ion outflow was observed just equatorward of millstone this is most likely due to heating from a latitudinally confined region of intense westward convection neutral meridional winds above millstone were obtained by three different techniques employing radar and fabry perot measurements the latitude variation of the winds was also estimated from radar measurements of hmf2 and electric fields using the servo model method strong equatorward nighttime neutral wind surges were found during both the march and april disturbances which reached the equatorward limit of the observations at f peak heights

an empirical model of the earth s horizontal wind fields hwm07 1 the new horizontal wind model hwm07 provides a statistical representation of the horizontal wind fields of the earth s atmosphere from the ground to the exosphere 0 500 km it represents over 50 years of satellite rocket and ground based wind measurements via a compact fortran 90 subroutine the computer model is a function of geographic location altitude day of the year solar local time and geomagnetic activity it includes representations of the zonal mean circulation stationary planetary waves migrating tides and the seasonal modulation thereof hwm07 is composed of two components a quiet time component for the background state described in this paper and a geomagnetic storm time component dwm07 described in a companion paper

multiradar observations of the polar tongue of ionization 1 we present a global view of large scale ionospheric disturbances during the main phase of a major geomagnetic storm we find that the low latitude auroral and polar latitude regions are coupled by processes that redistribute thermal plasma throughout the system for the large geomagnetic storm on 20 november 2003 we examine data from the high latitude incoherent scatter radars at millstone hill sondrestrom and eiscat tromso with superdarn hf radar observations of the high latitude convection pattern and dmsp observations of in situ plasma parameters in the topside ionosphere we combine these with north polar maps of stormtime plumes of enhanced total electron content tec derived from a network of gps receivers the polar tongue of ionization toi is seen to be a continuous stream of dense cold plasma entrained in the global convection pattern the dayside source of the toi is the plume of storm enhanced density sed transported from low latitudes in the postnoon sector by the subauroral disturbance electric field convection carries this material through the dayside cusp and across the polar cap to the nightside where the auroral f region is significantly enhanced by the sed material the three incoherent scatter radars provided full altitude profiles of plasma density temperatures and vertical velocity as the toi plume crossed their different positions under the cusp in the center of the polar cap and at the midnight oval polar cap boundary greatly elevated f peak density 1 5e12 m 3 and low electron and ion temperatures 2500 k at the f peak altitude characterize the sed toi plasma observed at all points along its high latitude trajectory for this event sed toi f region tec 150 1000 km was 50 tecu both in the cusp and in the center of the polar cap large upward directed fluxes of o 1 e14 m 2 s 1 were observed in the topside ionosphere

on the generation decay of the storm enhanced density plumes role of the convection flow and field aligned ion flow storm enhanced density sed plumes are prominent ionospheric electron density increases at the dayside middle and high latitudes the generation and decay mechanisms of the plumes are still not clear we present observations of sed plumes during six storms between 2010 and 2013 and comprehensively analyze the associated ionospheric parameters within the plumes including vertical ion flow field aligned ion flow and flux plasma temperature and field aligned currents obtained from multiple instruments including gps total electron content tec poker flat incoherent scatter radar pfisr super dual auroral radar network and active magnetosphere and planetary electrodynamics response experiment the tec increase within the sed plumes at the pfisr site can be 1 4 5 5 times their quiet time value the plumes are usually associated with northwestward e b flows ranging from a couple of hundred m s 1 to 1 km s 1 upward vertical flows due to the projection of these e b drifts are mainly responsible for lifting the plasma in sunlit regions to higher altitude and thus leading to plume density enhancement the upward vertical flows near the poleward part of the plumes are more persistent while those near the equatorward part are more patchy in addition the plumes can be collocated with either upward or downward field aligned currents facs but are usually observed equatorward of the peak of the region 1 upward fac suggesting that the northwestward flows collocated with plumes can be either subauroral or auroral flows furthermore during the decay phase of the plume large downward ion flows as large as 200 m s 1 and downward fluxes as large as 1014 m 2 s 1 are often observed within the plumes in our study of six storms enhanced ambipolar diffusion due to an elevated pressure gradient is able to explain two of the four large downward flow flux cases but this mechanism is not sufficient for the other two cases where the flows are of larger magnitude for the latter two cases enhanced poleward thermospheric wind is suggested to be another mechanism for pushing the plasma downward along the field line these downward flows should be an important mechanism for the decay of the sed plumes

fully coupled hydrogeophysical inversion of a laboratory salt tracer experiment monitored by electrical resistivity tomography 1 we perform a salt tracer experiment monitored by time lapse electrical resistivity tomography in a quasi two dimensional sandbox with the aim of determining the hydraulic conductivity distribution in the domain we use sodium chloride as a tracer together with cochineal red for visual monitoring the time series of observed resistance for each electrode configuration is characterized by its temporal moments we invert the mean arrival time of electrical potential perturbations and a few steady state hydraulic head measurements using the fully coupled hydrogeophysical approach recently introduced by pollock and cirpka 2010 this is the first application of the approach to experimental data the results obtained show a reasonable agreement between the estimated hydraulic conductivity field and the pattern of the actual sandbox filling using this estimation a transient simulation is performed to compute the propagation of the salt tracer plume through the sandbox the latter is compared to pictures taken during the experiment these results show an even better agreement indicating that the lenses of different sand types are not entirely homogeneous and some unexpected preferential flow paths are present we conclude that temporal moments of potential perturbations obtained during salt tracer tests provide a good basis for inferring the hydraulic conductivity distribution by fully coupled hydrogeophysical inversion

a dayside ionospheric positive storm phase driven by neutral winds 1 this paper presents observations and numerical simulations of ionospheric and thermospheric disturbances associated with a moderate geomagnetic storm on 10 september 2005 during the event the incoherent radars located in millstone hill and arecibo observed a dayside positive storm phase as manifested by the enhanced electron density in the f region the universal time ut altitude profile of electron density measured by both radars displayed a structure that closely resembles the greek letter a similar structure is also reproduced by the thermosphere ionosphere electrodynamics general circulation model tiegcm this peculiar electron density distribution is found to be associated with vertical ion drift which initially was upward and then became downward using realistic time dependent ionospheric convection and auroral precipitation as inputs the tiegcm reveals that the primary cause of the positive storm response was the enhanced meridional neutral wind rather than the penetration magnetospheric electric field this study reiterates the importance of neutral wind effects on ionospheric disturbance

assessment of the non hydrostatic effect on the upper atmosphere using a general circulation model gcm 1 under hydrostatic equilibrium a typical assumption used in global thermosphere ionosphere models the pressure gradient in the vertical direction is exactly balanced by the gravity force using the non hydrostatic global ionosphere thermosphere model gitm which solves the complete vertical momentum equation the primary characteristics of non hydrostatic effects on the upper atmosphere are investigated our results show that after a sudden intense enhancement of high latitude joule heating the vertical pressure gradient force can locally be 25 larger than the gravity force resulting in a significant disturbance away from hydrostatic equilibrium this disturbance is transported from the lower altitude source region to high altitudes through an acoustic wave which has beensimulated inaglobal circulation model forthefirst time due to the conservation of perturbation energy the magnitude of the vertical wind perturbation increases with altitude andreaches 150 250 m sat300 430 kmduringthe disturbance the upward neutral wind lifts the atmosphere and raises the neutral density at high altitudes by more than 100 these large vertical winds are not typically reproduced by hydrostatic models of the thermosphere and ionosphere our results give an explanation of the cause of such strong vertical winds reported in many observations citation deng y a d richmond a j ridley and h l liu 2008 assessment of the non hydrostatic effect on the upper atmosphere using a general circulation model gcm geophys res lett 35 l01104 doi 10 1029 2007gl032182

observations of ion neutral coupling associated with strong electrodynamic disturbances during the 2015 st patrick s day storm we use incoherent scatter radar observations at millstone hill mho and arecibo ao and topside ionosphere in situ dmsp observations during the great geomagnetic storm on 17 18 march 2015 to conduct a focused study on ion neutral coupling and storm time ionosphere and thermosphere dynamics some of these observations were made around the time of large ionospheric drifts within a sub auroral polarization stream saps during the storm main phase we identify multiple disturbance characteristics in the north american late afternoon and dusk sector 1 strong sub auroral westward drifts occurred between 20 24 ut near mho accompanied by a storm enhanced density plume passage over mho in the afternoon with a poleward upward ion drift the strongly westward flow reached 2000 m s speed near the poleward plume edge 2 prompt penetration electric field signatures appearing as poleward upward ion drifts on the dayside over both mho and ao were consistent with dmsp vertical drift data and contributed to plume development 3 meridional wind equatorward surges occurred during daytime hours at mho followed by 2 3 hr period oscillations at both mho and ao the zonal electric field at ao was strongly correlated with the wind oscillation 4 large ion temperature enhancements as well as 50 m s upward ion drifts throughout the e and f regions were observed during the saps period these were presumably caused by strong frictional heating due to large plasma drifts the heating effects appeared to drive significant atmospheric upwelling and corresponding ion upflow was also observed briefly this study highlights some of the important effects of fast plasma transport as well as other disturbance dynamics on ion neutral coupling during a single intensification period within a great geomagnetic storm

average characteristics and activity dependence of the subauroral polarization stream 1 data from the millstone hill incoherent scatter radar taken over two solar cycles 1979 2000 are examined to determine the average characteristics of the disturbance convection electric field in the midlatitude ionosphere radar azimuth scans provide a regular database of ionospheric plasma convection observations spanning auroral and subauroral latitudes and these scans have been examined for all local times and activity conditions we examine the occurrence and characteristics of a persistent secondary westward convection peak which lies equatorward of the auroral two cell convection individual scans and average patterns of plasma flow identify and characterize this latitudinally broad and persistent subauroral polarization stream saps which spans the nightside from dusk to the early morning sector for all kp greater than 4 premidnight the saps westward convection lies equatorward of l 4 60 invariant latitude spans 3 5 of latitude and has an average peak amplitude of 900 m s in the predawn sector saps is seen as a region of antisunward convection equatorward of l 3 55 spanning 3 of latitude with an average peak amplitude of 400 m s

responses in the polar and equatorial ionosphere to the march 2015 st patrick day storm the st patrick day storm of 2015 17 march 2015 occurred at a unique time when there were multiple spacecraft observing the earth s ionosphere between 350 and 885 km observations of the plasma flows and densities from the five operational polar orbiting dmsp spacecraft combined with those from the equatorial orbiting c nofs spacecraft provided a comprehensive global record of the both the polar and equatorial ionosphere regions responses to the storm this paper presents an overview of the data from this suite of spacecraft focusing on the following aspects 1 the polar cap ionosphere s reaction to the storm 2 the change in the penetration electric field in the midlatitude region as a function of time and the solar local time during the storm 3 the equatorial ionosphere s response of the meridional vertical flows to the penetration electric field and the disturbance dynamo during the storm and 4 the creation of a predawn ionospheric bubble system near the equator during the storm s main phase that was observed at low altitudes by c nofs and later at high altitudes by several dmsp examining these phenomenon enable us to trace the dynamic flow of energy from the solar wind input in the polar ionosphere all the way to the equatorial ionosphere

a large scale traveling ionospheric disturbance during the magnetic storm of 15 september 1999 enhancement of gps total electron content 1 0 10 16 m 2 multipoint and imaging observations of these parameters show that the lstid moved equatorward over japan with a velocity of 400 450 m s from a comparison with the sheffield university plasmasphere ionosphere model supim we conclude that an enhancement 250 300 m s of poleward neutral wind that is propagating equatorward caused these observational features of the lstid at midlatitudes to investigate generation of the lstid by auroral energy input we have used auroral images obtained by the polar uvi instrument magnetic field variations obtained at multipoint ground stations and the empirical joule heating rate calculated by the assimilative mapping of ionospheric electrodynamics amie technique intense auroral energy input was observed at 0800 1100 ut 4 6 hours before the lstid probably causing equatorward neutral wind at lower latitudes it is likely that the poleward wind pulse that caused the observed lstid was generated associated with the cessation of this equatorward wind the effect of lorentz force is also discussed index terms 0310 atmospheric composition and structure airglow and aurora 2427 ionosphere ionosphere atmosphere interactions 0335 2435 ionosphere ionospheric disturbances 2437 ionosphere ionospheric dynamics 2788 magnetospheric physics storms and substorms keywords large scale traveling ionospheric disturbance thermosphere ionosphere coupling magnetic storm airglow imaging gps network ionosonde

storm time plasma transport at middle and high latitudes associated with the large scale enhancement of the ionospheric convection electric field during disturbed geomagnetic conditions solar produced f region plasma is transported to and through the noontime cleft from a source region at middle and low latitudes in the afternoon sector as a result of the offset between the geomagnetic and geographic poles the afternoon sector region of strong sunward convection is shifted to increasingly lower geographic latitude throughout the interval between 12 ut and 24 ut a snowplow effect occurs in which the convection cell continually encounters fresh corotating ionospheric plasma along its equatorward edge producing a latitudinally narrow region of storm enhanced plasma density sed and increased total electron content which is advected toward higher latitudes in the noon sector the millstone hill incoherent scatter radar regularly observes sed as a spatially continuous large scale feature spanning local times between noon and midnight and at latitudes between the polar cap and its mid or low latitude source region for local times away from noon the latitude of most probable sed occurrence moves equatorward by 6 for an increase of 2 in the kp index during strong disturbances the topside sed is observed to be convecting sunward at 750 m s 1 with a flux of 1014 m 2 s 1 this feature accounts for the pronounced enhancement of ionospheric density near dusk at middle latitudes observed during the early stages of magnetic storms called the dusk effect and constitutes a source for the enhanced f region plasma observed in the polar cap during disturbed conditions

ionospheric climatology and variability from long term and multiple incoherent scatter radar observations climatology in eastern american sector 1 ionospheric climatology and variability studies are conducted using long term incoherent scatter radar isr observations from seven sites around the world these studies result in an empirical model system the isr ionospheric model isrim which represents local and regional ionospheric climatology and variability of the ionosphere this paper addresses some new climatological features revealed by the model for latitudes spanning 18 70 n over the eastern american sector the latitudinal change of the f2 layer electron density exhibits a clear depletion near millstone hill latitudes when solar activity is median or low accompanied by a te enhancement and electron density peaks at 10 both to the north and south of millstone hill possible explanations are discussed we also characterize several types of variation in plasma temperatures in this region including ion temperature elevation for quiet conditions in the auroral zone and electron temperature increases toward higher latitudes

dwm07 global empirical model of upper thermospheric storm induced disturbance winds 1 we present a global empirical disturbance wind model dwm07 that represents average geospace storm induced perturbations of upper thermospheric 200 600 km altitude neutral winds dwm07 depends on the following three parameters magnetic latitude magnetic local time and the 3 h kp geomagnetic activity index the latitude and local time dependences are represented by vector spherical harmonic functions up to degree 10 in latitude and order 3 in local time and the kp dependence is represented by quadratic b splines dwm07 is the storm time thermospheric component of the new horizontal wind model hwm07 which is described in a companion paper dwm07 is based on data from the wind imaging interferometer on board the upper atmosphere research satellite the wind and temperature spectrometer on board dynamics explorer 2 and seven ground based fabry perot interferometers the perturbation winds derived from the three data sets are in good mutual agreement under most conditions and the model captures most of the climatological variations evident in the data