With the advent of the Heliophysics/Geospace System Observatory (H/GSO), a complement of multi-spacecraft missions and ground-based observatories to study the space environment, data retrieval, analysis, and visualization of space physics data can be daunting. The Space Physics Environment Data Analysis System (SPEDAS), a grass-roots software development platform ( www.spedas.org ), is now officially supported by NASA Heliophysics as part of its data environment infrastructure. It serves more than a dozen space missions and ground observatories and can integrate the full complement of past and upcoming space physics missions with minimal resources, following clear, simple, and well-proven guidelines. Free, modular and configurable to the needs of individual missions, it works in both command-line (ideal for experienced users) and Graphical User Interface (GUI) mode (reducing the learning curve for first-time users). Both options have “crib-sheets,” user-command sequences in ASCII format that can facilitate record-and-repeat actions, especially for complex operations and plotting. Crib-sheets enhance scientific interactions, as users can move rapidly and accurately from exchanges of technical information on data processing to efficient discussions regarding data interpretation and science. SPEDAS can readily query and ingest all International Solar Terrestrial Physics (ISTP)-compatible products from the Space Physics Data Facility (SPDF), enabling access to a vast collection of historic and current mission data. The planned incorporation of Heliophysics Application Programmer’s Interface (HAPI) standards will facilitate data ingestion from distributed datasets that adhere to these standards. Although SPEDAS is currently Interactive Data Language (IDL)-based (and interfaces to Java-based tools such as Autoplot), efforts are under-way to expand it further to work with python (first as an interface tool and potentially even receiving an under-the-hood replacement). We review the SPEDAS development history, goals, and current implementation. We explain its “modes of use” with examples geared for users and outline its technical implementation and requirements with software developers in mind. We also describe SPEDAS personnel and software management, interfaces with other organizations, resources and support structure available to the community, and future development plans. Electronic Supplementary Material The online version of this article (10.1007/s11214-018-0576-4) contains supplementary material, which is available to authorized users.

[1] In a homogeneous anisotropic plasma the magnetohydrodynamic (MHD) shear Alfvén wave may become unstable for p k > p ? + B 2 /m o . Recently, a new type of fire-hose instability was found by Hellinger and Matsumoto [2000] that has maximum growth rate occurring for oblique propagation and may grow faster than the Alfvén mode. This new mode is compressional and may be more efficient at destroying pressure anisotropy than the standard fire hose. This paper examines the fire-hose type ( p k > p ? ) instabilities based on the linear and nonlinear double-polytropic MHD theory. It is shown that there exist two types of MHD fire-hose instabilities, and with suitable choice of polytropic exponents the linear instability criteria become the same as those based on the Vlasov theory in the hydromagnetic limit. Moreover, the properties of the nonlinear MHD fire-hose instabilities are found to have great similarities with those obtained from the kinetic theory and hybrid simulations. In particular, the classical fire-hose instability evolves toward the linear fire-hose stability threshold, while the nonlinear marginal stability associated with the new fire hose is well below the condition of b k À b ? = 2 but complies with less stringent linear stability threshold for compressible Alfvén waves.

In this study, we describe small-scale density depletions of cold electrons associated with electrostatic electron cyclotron harmonic (ECH) waves observed by the ERG (Exploration of energization and Radiation in Geospace) spacecraft during a plasmapause crossing near the magnetic equator in the postmidnight sector. The total electron density was roughly 2 orders of magnitude larger than that of the hot electrons, indicating existence of a cold and dense electron population below ∼20 eV. The cold electron density profile showed small-scale density depletion regions, in which the ECH emissions were intensified. Moreover, a flux enhancement of hot electrons in the perpendicular direction was also associated with the ECH emissions intensity. This relation suggests perpendicular energization of electrons by electric field oscillation of the ECH waves.Plain Language Summary This study clarifies a relation of cold-electron density irregularities and electron cyclotron harmonic (ECH) waves, both of which are frequently observed in the inner magnetosphere but their relation had not been clearly indicated by observations. We analyzed a plasmapause crossing event on 12 April 2017 observed by the ERG spacecraft and found that the plasmapause had small-scale density depletions of cold electrons and ECH emissions were intensified inside the depletion regions. This suggests that an ECH emission intensity can be controlled by a background cold-electron population. In addition, enhancements of hot-electron fluxes in the direction perpendicular to the local magnetic field were also observed in response to the ECH emissions. This is probably due to perpendicular energization of cold electrons by the oscillating electric field of the ECH waves. The close relation between cold electrons and ECH emission intensification, shown in this analysis, gives indication of leakage of ionospheric cold electrons and its control of equatorial ECH waves just outside the plasmapause.