News & Events

  • Evolution of the Earth's Van Allen Radiation Belts

    April 2, 2014

    The evolution of the Earth's Van Allen Radiation Belts is being modeled by following test particle trajectories in 2D and 3D simulations using 3D magnetohydrodynamic fields from the Lyon-Fedder-Mobarry MHD code driven by measured plasma parameters from spacecraft in the solar wind upstream from Earth. Global electric and magnetic field structure and computed particle distributions in momentum and spatial location are compared with measurements from the recently launched (August 30, 2012) Van Allen Probes satellites. This work is supported by the NASA Heliophysics Directorate.

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  • Green Cube

    April 2, 2014

    The undergraduates in the JPL-sponsored GreenCube project of the Lynch Rocket Lab, are developing a CubeSat-class autonomous sensor payload, which they fly on balloons across New Hampshire and this spring will be floating in an array down the Connecticut (and other) River(s). ``Cubesat'' is a small satellite prototype established by CalPoly and Stanford Universities. Similar satellites have been used by many other universities and student satellite programs because of its relatively easy and inexpensive design.

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  • Mechanism for higher harmonic radio emission from aurorae

    April 2, 2014

    It has long been known that the aurora emit radio waves at the second and third harmonics of the electron cyclotron frequency. A detailed theory explaining these emissions has been developed and tested in many experiments. However, recently (in 2012) the fourth and fifth harmonics were observed for the first time. While it is possible that the same theoretical explanation applies to them, there is some evidence that their polarization may be inconsistent with the mechanism that generates the lower harmonics.

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  • Understanding wave-particle interactions in Earth's polar cusps

    April 2, 2014

    The polar cusps are two funnel-like regions near the poles of Earth's approximately dipolar magnetic field, one in each hemisphere, where the Earth's magnetic field may directly connect to that of the solar wind. The interaction of the solar wind and its magnetic field with Earth's magnetic field gives rise to unusual effects in the cusp leading to particular distributions of accelerated and non-accelerated charged particles, which in turn generate plasma waves and interact with pre-existing plasma waves.

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