AB STRACTThe Tai wan/US FORMOSAT-3/COS MIC (FORMOsa SAT el lite mis sion -3/Con stel la tion Ob serv ing Sys tem for Me te o rol ogy, Ion o sphere and Cli mate) sat el lite con stel la tion was suc cess fully launched on 14 April 2006. It is ex pected to le ver age the use of the GPS (Global Po si tion ing Sys tem) ra dio occultation data for at mo spheric and ion o spheric re search to im prove global weather fore casts and aid cli mate change re lated stud ies. FORMOSAT-3/COS MIC, to gether with the Eu ro pean MetOp, Ger man CHAMP and US/Ger man GRACE-A sat el lites, form a 9 sat el lite con stel la tion for pre cise at mo spheric sound ing on a global scale. This sat el lite con stel la tion is expected to provide about 3500 occultation measurements daily.Re cent re sults and the sta tus of the CHAMP and GRACE-A or bit and occultation data anal y sis are re viewed and com ple mented with a re view of ini tial re sults from FORMOSAT-3/COS MIC at GFZ. The sig nif i cantly in creased po ten tial of the CHAMP, GRACE-A and FORMOSAT-3/COS MIC con stel la tion for at mo spheric stud ies, com pared to sin gle sat el lite mis sions, is dem on strated for se lected ap pli ca tions such as global mon i tor ing of wa ter va por dis tri bu tions, tropo pause parameters and ionospheric irregularities.

A global stability analysis of mirror modes in the magnetosheath is presented.The analysis is based upon the kinetic-MHD formulation which includes relevant kinetic effects such as Landau resonance and gradient drift effects related to inhomogeneities in the background density, temperature, pressure and its anisotropy, magnetic field, and plasma flow velocity. Pressure anisotropy provides the free energy for the global mirror mode. The local theory of mirror modes predicts purely growing modes confined in the unstable magnetosheath region; however, the nonlocal theory that includes the effects of gradients and plasma flow predicts modes with real frequencies which propagate with the flow from the magnetosheath toward the magnetopause boundary. The real frequency is on the order of a combination of the diamagnetic drift frequency and the Doppler shift frequency associated with plasma flow. The diamagnetic drift frequency provides a wave phase velocity in the direction of the magnetopause so that wave energy accumulates against the magnetopause boundary, and the amplitude is skewed in that direction. On the other hand, plasma flow also gives rise t o a real phase velocity, but the phase velocity is smaller than the flow velocity. As a result, the wave amplitude is increased in the wake of the plasma flow and piles up against the bow shock boundary.

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With the first injection of neutral beams into the National Spherical Torus Experiment (NSTX) [Ono, et al., Nucl. Fusion 40 (2000) p557] a broad spectrum of fluctuations consisting of nearly equally spaced peaks in the frequency range from about 0.2 to 1.2 times the ion cyclotron frequency was observed. The frequencies scale with toroidal field and plasma density consistently with Alfvén waves. From these and other observations, the modes have been identified as Compressional Alfvén Eigenmodes (CAE). It has also recently been found that the ratio of the measured ion and electron temperatures in NSTX during neutral beam heating is anomalously high [Bell, Bull. Am. Phys. Soc. 46, p206 (2001)]. To explain the anomaly in the ratio of ion to electron temperature, it has been suggested that the CAE, driven by the beam ions, stochastically heat the thermal ions [Gates, et al., PRL 87, p205003 (2001)]. In this paper it is shown through studies of the power balance that stochastic heating of the thermal ions by the observed CAE alone is not solely responsible for the anomaly in the ion to electron temperature ratio.

Abstract. Measurements of high frequency oscillations in JET, JT-60U, Alcator C-Mod, DIII-D and TFTR plasmas are contributing to a new understanding of fast ion driven instabilities relevant to Advanced Tokamak (AT) regimes. A model based on the transition from a cylindrical-like frequency-chirping mode to the Toroidal Alfvén Eigenmode (TAE) has successfully encompassed many of the characteristics seen in experiments. In a surprising development, the use of internal density fluctuation diagnostics has revealed many more modes than has been detected on edge magnetic probes. A corollary discovery is the observation of modes excited by fast particles traveling well below the Alfvén velocity. These observations open up new opportunities for investigating a "sea of Alfvén Eigenmodes" in present scale experiments, and highlight the need for core fluctuation and fast ion measurements in a future burning plasma experiment.