Thermosphere Research Articles

Design of laser retro-reflectors and experiment of laser ranging for PN1B satellite

PN1Bexperimental satellite is an initiative project of China aiming at thermosphere density detection, which has been successfully launched into outer space from Taiyuan Satellite Launch Center in September, 2015. In order to satisfy the inspection standard and high precision measurement application requirements for the satellite GPS orbit determination data, and according to fact that the satellite could not provide the required installation area for the array structure of laser reflectors, PN1B satellite is equipped with multiple small (10 mm) cube prisms for satellite laser ranging. After sending the satellite into orbit, the TROS1000 mobile satellite laser ranging system was used for the tracking and laser ranging experiments. The measurement results show that the laser echo data are enough, the average number of photons per second laser echo is as high as 173, marking such small laser reflectors as the cube prisms will play an important role in the application of precise orbit determination.

Impact of the interaction between the quasi‐2 day wave and tides on the ionosphere and thermosphere

AbstractThe quasi‐2 day wave (QTDW) can effectively interact with atmospheric tides in the mesosphere and lower thermosphere. We study the effect of this QTDW‐tidal interaction on the ionosphere and thermosphere using the thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model. This interaction reduces the amplitude of the migrating diurnal tide in the lower thermosphere by ~10 m/s in neutral winds and also generates sum and difference secondary waves in the lower thermosphere and E region ionosphere. As a result of the changed migrating diurnal tide and sum/difference secondary wave, vertical ion drift varies with local time at different longitudes by ~5 m/s. In addition, the changed migrating diurnal tide also modulates the thermospheric composition (O/N2). During a QTDW event, the ionosphere F2 region peak electron density (NmF2) is reduced due to the mixing effect of the QTDW dissipation; NmF2 also shows changes in local time variation due to the QTDW‐tidal interaction. The sum and difference secondary waves can cause additional oscillations in vertical ion drift and ionospheric electron densities. The QTDW‐tidal interaction is another mechanism by which the QTDW impacts the ionosphere and thermosphere, along with other mechanisms: QTDW modulation of the E region wind dynamo with a period of quasi‐2 days and QTDW dissipation induced mixing in the thermosphere.

News in Brief: Thinner thermosphere

News in Brief: Thinner thermosphere

Polluting space [CO/sub 2/ effects on the thermosphere

Polluting space [CO/sub 2/ effects on the thermosphere

한반도 상공 고층대기의 중간 자외선 대기광 모델

For the planned experiments of Korea Sounding Rocket-III (KSR-III), we have constructed a model of MUV dayglow in the mid-latitude. The model computes relative intensities of individual emission lines in the Vegard-Kaplan and 2PG band systems of in the wavelength range of 2500-3500. In addition to the emission lines, solar scattered continuum was computed by an extended LOWTRAN7 code, in which we have included solar scattering in altitudes higher than 100 km by using MSIS90 thermosphere model. Ratios among vibrational bands of VK and 2PG system, were computed from the observed MUV dayglow spectra of Cleary et al. (1995). The model provides MUV dayglow intensitiy profiles with a wavelength resolution of 3.13 as a function of altitude. The computed intensity profiles have been utilized in designing the KSR-III airglow photometers.

COSMIC GPS Ionospheric Sensing and Space Weather

As our civilization becomes more dependent on space based technologies, we become more vulnerable to conditions in space weather. Accurate space weather specification and forecasting require proper modeling which account for the coupling between the sun, the magnetosphere, the thermo sphere, the ionosphere and the mesosphere. In spite of the tremendous advances that have been made in understanding the physics behind different space weather phenomena, the ability to specify or predict space weather is limited due to the lack of continuous and extensive observations in these regions. Placing a constellation of GPS receivers in low-Earth orbit, such as the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), provides an extremely powerful system for continuously and extensively measuring one of these regions, the ionosphere. COSMIC, by use of GPS occultations, will make it possible to obtain continuous and global3-dimensional images of electron density, irregularities and TIDs in the ionosphere and plasmasphere. COSMIC would provide nearly 5600 globally distributed occultations per day suitable for ionospheric sensing. Occultations can be processed individually to obtain vertical profiles of electron density, with vertical resolution of ~lkm, or collectively by means of tomography or data assimilation to obtain 3-D images of electron density or irregularity structure. In this paper we describe the GPS observables for ionospheric sensing and the occultation geometry. Our presentation evolves from discussing simple to more complicated inversion techniques starting with the Abel inversion, gradient-constrained Abel inversion, tomography, and finally data assimilation. In each of these techniques, the accuracy is assessed either via examination of real data from GPSIMET or via simulation. Brief discussions of measuring ionospheric irregularities and TIDs are given.

Comment on “The O2 atmospheric dayglow in the thermosphere” by M. R. Torr, B. Y. Welsh, and D. G. Torr

Comment on “The O₂ atmospheric dayglow in the thermosphere” by M. R. Torr, B. Y. Welsh, and D. G. Torr

Solar EUV heating efficiencies in the thermosphere

Modele de chauffage UV de la thermosphere utilisant les nouvelles donnees de satellite dans les modeles de Torr et al. (1980) et de Fuller-Rowell et Rees (1980, 1981)

Winds in the Thermosphere

Winds in the Thermosphere