Kappa Distribution Function Effects on Landau Damping in Electrostatic Vlasov Simulation

The non-thermal high-energy electron effects on Langmuir wave-particle interaction are investigated using an initial value approach. A Vlasov-Poisson simulation is employed based on the splitting scheme by Cheng and Knorr (1976). The kappa distribution function is taken as an example of non-thermal electrons. The modification is manifested as an increase in the Landau damping rate and a decrease in the real frequency for a long wavelength limit. A part of the analyses using the modified plasma dispersion function (Summers and Thorne 1991) is reproduced for £e = 2, 3 and 6. The dispersion relation from the initial value simulation and the plasma dispersion function compare favorably.(PACS numbers: 52.35.Fp, 52.35.Sb, 52.65.Ff)

Radio Occultation Retrieval of Atmospheric Profiles from the FORMOSAT-3/COSMIC Mission: Early Results

Six identical micro-satellites of the FORMOSAT-3/COSMIC (Formosa Satellite #3 and Constellation Observing System for Meteorology, Ionosphere and Climate: FS-3/C) mission were successfully launched on 14 April 2006. The FS-3/C mission provides the first satellite constellation for monitoring global weather using the Global Positioning System (GPS) radio occultation (RO) technique. The mission¡¦s primary scientificific goal is to obtain near-real time profiles of the bending angle and refractivity in the neutral atmosphere and in the ionosphere. In April, 2007 the FS-3/C mission provide about RO soundings of 2000 atmospheric vertical profiles per day in a nearly uniform distribution around the globe. The lowest altitude penetration for more than 80% of RO soundings reached below 1 kmin altitude. Most soundings have penetration below 800m altitude in the equatorial region and below 200 m altitude in polar regions. The quality and accuracy of the RO sounding profiles are in good agreement with the CHAMP(CHAllenging Minisatellite Payload) RO soundings and direct measurements using dropsondes. The FS-3/C RO sounding observations are used to support operational global weather prediction, climate monitoring and research, space weather forecasting, and ionosphere and gravity research

Distribution of water-group ion cyclotron waves in Saturn’s magnetosphere

Abstract The water-group ion cyclotron waves (ICWs) in Saturn’s magnetosphere were studied using the magnetic field data provided by the MAG magnetometer on board the Cassini satellite. The period from January 2005 to December 2009, when the Cassini radial distance is smaller than 8 R S , was used. ICWs were identified by their left-hand circularly polarized magnetic perturbations and wave frequencies near the water-group ion gyrofrequencies. We obtained the spatial distribution of ICW amplitude and found that the source region of ICWs is mostly located in the low-latitude region, near the equator and inside the 6 R S radial distance. However, it can extend beyond 7 R S in the midnight region. In general, the wave amplitude is peaked slightly away from the equator, for all local time sectors in both the Northern and Southern Hemispheres. By assuming that the water-group ions are composed of pickup ions and background thermal ions, we obtained the local instability condition of the ICWs and estimated their growth rate along the field lines. If the wave amplitude is correlated with the growth rate, the observed latitudinal dependence of the wave amplitude can be well explained by the local stability analysis. Also, latitudinal location of the peak amplitude is found to depend on the local time. This implies a local time dependence for the water-group ion parallel temperature T|, as determined from the theoretical calculations. Graphical abstract Figure 7. The upper panel shows the projected orbit of Cassini in the cylindrical R–Z plane across the L-shell from the Northern Hemisphere to the Southern Hemisphere. The red line denotes Cassini’s orbit and the blue lines denote the L-shell field lines going through points A and B, respectively. The lower panel shows the power spectrum of $$\delta B_{\phi }$$ δ B ϕ , the blue dotted line shows the local W+ gyrofrequency (f local), and the black line is the W+ gyrofrequency at the equator (f eq) of the dipole L-shell of the Cassini orbit, which moves from A to

Correction to: Distribution of water-group ion cyclotron waves in Saturn’s magnetosphere

Abstract After publication of this work (Chou and Cheng 2017), an error was noticed. In the Acknowledgements section, the wrong institution name was given as ‘the National Science Council of Taiwan’. However, the correct institution name should be ‘the Ministry of Science and Technology of Taiwan’

Preface to the Special Issue on FORMOSAT-3/COSMIC Mission Early Results

Six identical micro-satellites comprising the FORMOSAT-3/COSMIC (Formosa Satellite #3 and Constellation Observing System for Meteorology, Ionosphere and Climate) mission were successfully launched into a circular low-Earth orbit from Vandenberg Air Force Base, California at 01:40 UTC on April 15, 2006. The FORMOSAT-3/COSMIC mission is a collaborative project jointly carried out by the National Space Organization (NSPO) in Taiwan and the University Corporation for Atmospheric Research (UCAR) in USA, with the participation of many governmental, academic and private institutions. Each FORMOSAT-3 satellite carries three primary science instruments: a GPS Occultation Experiment (GOX) payload, a Tiny Ionospheric Photometer (TIP), and a Tri-Band Beacon (TBB) payload. The GOX provides vertical sounding of atmospheric profiles around the globe and electron density profiles in the ionosphere. The TIP instrument is a narrow band far-ultraviolet radiometer; it operates in the 131.0 _{ 160.0 nm bandwidth with a focus wavelength at 135.6 nm to measure the line-of-sight total electron content. The TBB transmits phase coherent, continuous signals at three frequencies: VHF (150.012 MHz), UHF (400.032 MHz), and L-band (1066.752 MHz) to provide ionospheric observations to ground-based receivers