Preliminary results of rocket attitude and auroral green line emission rate in the DELTA campaign

Iwagami, N.; Komada, Sayaka; Takahashi, Tsuyoshi

doi:10.1186/bf03351999

Cited by 3 publications

(2 citation statements)

References 8 publications

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“…The peak altitude of q p was 115–120 km around the period of the rocket launch and 105–110 km after 01:00 UT. Iwagami et al [2006] estimated the characteristic energy of the precipitating auroral electrons during the rocket flight to be 4 keV, by comparing the observed peak altitude of the green line emission [ Kurihara et al , 2006] with the calculated green line volume emission rate for unit incident flux [ Banks et al , 1974]. The peak altitudes of q p during the rocket flight are consistent with the calculated ionization rate for the characteristic energy of 4 keV that peaks around 120 km [ Banks et al , 1974].…”

Section: Auroral Heating Rate Estimationmentioning

confidence: 77%

Temperature enhancements and vertical winds in the lower thermosphere associated with auroral heating during the DELTA campaign

et al. 2009

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[1] A coordinated observation of the atmospheric response to auroral energy input in the polar lower thermosphere was conducted during the Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA) campaign. N 2 rotational temperature was measured with a rocket-borne instrument launched from the Andøya Rocket Range, neutral winds were measured from auroral emissions at 557.7 nm with a Fabry-Perot Interferometer (FPI) at Skibotn and the KEOPS, and ionospheric parameters were measured with the European Incoherent Scatter (EISCAT) UHF radar at Tromsø. Altitude profiles of the passive energy deposition rate and the particle heating rate were estimated using data taken with the EISCAT radar. The local temperature enhancement derived from the difference between the observed N 2 rotational temperature and the MSISE-90 model neutral temperature were 70-140 K at 110-140 km altitude. The temperature increase rate derived from the estimated heating rates, however, cannot account for the temperature enhancement below 120 km, even considering the contribution of the neutral density to the estimated heating rate. The observed upward winds up to 40 m s À1 seem to respond nearly instantaneously to changes in the heating rates. Although the wind speeds cannot be explained by the estimated heating rate and the thermal expansion hypothesis, the present study suggests that the generation mechanism of the large vertical winds must be responsible for the fast response of the vertical wind to the heating event.

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Section: Auroral Heating Rate Estimationmentioning

confidence: 77%

Temperature enhancements and vertical winds in the lower thermosphere associated with auroral heating during the DELTA campaign

et al. 2009

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“…For example, it is well known that the ground-based FPI measurements have a problem with the assumption of the auroral emission layer heights, and it is difficult to find a region where the thermospheric wind is measured. A comparison between in-situ measurement of neutral temperature by the NTV on Iwagami et al (2006) the rocket and remote measurements by the FPI from the ground will provide information useful for estimating the effective emission height. Thus, an integrated analysis of the in-situ measurement and the ground based observation enables us to study the thermospheric dynamics or energetics from further insight.…”

Section: Campaign Objectivesmentioning

confidence: 99%

Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA)—Japanese sounding rocket campaign—

et al. 2006

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Japanese sounding rocket "S-310-35" was launched from Andøya Rocket Range in Norway on December 13, 2004 during Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA) campaign, in which the rocket-borne in-situ measurements and ground-based measurements were coordinated to carry out a comprehensive observation of the thermospheric response against the auroral energy input. The instruments on board the rocket successfully performed their measurements during the flight, and thereby the temperature and density of molecular nitrogen, auroral emission rate, and the ambient plasma parameters were derived. Simultaneous measurements by the ground-based instruments provided neutral wind, neutral temperature, the auroral images and the ionospheric parameters near the rocket trajectory. This paper introduces science objectives, experimental outline, and preliminary scientific results of the DELTA campaign and explains geophysical condition at the time of the rocket launch, while the companion papers in this special issue describe more detailed results from each instrument. Key words: Lower thermosphere, dynamics, energetics, sounding rocket, aurora. Science BackgroundAuroral energy inputs from the magnetosphere in the form of electric fields and energetic particles are deposited mainly in the lower thermosphere (90-150 km) by Joule and particle heating, and the dissipation rates of the auroral energies can exceed that of other energy sources such as solar ultraviolet radiation (Roble, 1995;Thayer and Semeter, 2004). Ion drag, which is the force exerted on neutral species by ions accelerated by the electric fields through ion-neutral collisions, transfers momentum to the neutral atmosphere and drives the neutral winds (Larsen et al., 1995;Richmond and Thayer, 2000). Moreover, collisions of precipitating particles with the neutral species lead to an increase in ionospheric conductivity, various chemical processes of ions and neutral species, changes in composition, and auroral emissions (Rees, 1989;Schunk and Nagy, 2000). For a better understanding of the complex interactions between the dynamics and the energetics in the coupled magnetosphere-ionosphere-thermosphere system, it is important to investigate the atmospheric response to auroral activities.Recent observations in the polar thermosphere have revealed the strong atmospheric response to auroral energy inputs. Strong neutral winds and wind shears are observed in the polar lower thermosphere during auroral disturbances using the chemical release technique in the seCopyright c The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences; TERRAPUB.ries of Atmospheric Response in Aurora (ARIA) rocket experiments (Larsen et al., 1997). The observed wind profiles show the presence of a jet around 110-120 km altitudes. The wind speeds of the jets increase and the hodograph is more likely linear as th...

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Observations of the lower thermospheric neutral temperature and density in the DELTA campaign

et al. 2006

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The rotational temperature and number density of molecular nitrogen (N 2 ) in the lower thermosphere were measured by the N 2 temperature instrument onboard the S-310-35 sounding rocket, which was launched from Andøya at 0:33 UT on 13 December 2004, during the Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA) campaign. The rotational temperature measured at altitudes between 95 and 140 km, which is expected to be equal to neutral temperature, is much higher than neutral temperature from the Mass Spectrometer Incoherent Scatter (MSIS) model. Neutral temperatures in the lower thermosphere were observed using the auroral green line at 557.7 nm by two Fabry-Perot Interferometers (FPIs) at Skibotn and the Kiruna Esrange Optical Platform System site. The neutral temperatures derived from the look directions closest to the rocket correspond to the rotational temperature measured at an altitude of 120 km. In addition, a combination of the all-sky camera images at 557.7 nm observed at two stations, Kilpisjärvi and Muonio, suggests that the effective altitude of the auroral arcs at the time of the launch is about 120 km. The FPI temperature observations are consistent with the in situ rocket observations rather than the MSIS model.

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Preliminary results of rocket attitude and auroral green line emission rate in the DELTA campaign

Cited by 3 publications

References 8 publications

Temperature enhancements and vertical winds in the lower thermosphere associated with auroral heating during the DELTA campaign

Temperature enhancements and vertical winds in the lower thermosphere associated with auroral heating during the DELTA campaign

Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA)—Japanese sounding rocket campaign—

Observations of the lower thermospheric neutral temperature and density in the DELTA campaign

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