skip to main content


Search for: All records

Creators/Authors contains: "Liemohn, M. W."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. R. Maggiolo, N. André (Ed.)
    This chapter focuses on emerging methods and capabilities enabling future breakthroughs in magnetospheric research. That is, it does not focus on magnetospheric research regions and science issues, but on how new trends in the scientific research is conducted. We specifically cover four topics emerging as techniques/issues that will likely cause a major upheaval in our approach to magnetospheric physics. The four topics are: the miniaturization of spacecraft systems and scientific instrumentation; high-end computing and advanced techniques in code coupling methodologies; storage and handling of large data sets, along with awareness of advanced statistical techniques; and diversity within the magnetospheric physics workforce. We think they are paradigm-shifting breakthroughs that will revolutionize many research areas within the science, technology, engineering, and mathematics umbrella 
    more » « less
  2. Abstract

    The 400 worst‐case severe environments for surface charging detected at Los Alamos National Laboratory satellites during the years of 1990–2005 as binned by the definitions of four criteria developed by Matéo‐Vélez et al. (2018,https://doi.org/10.1002/2017sw001689) and the solar wind and Interplanetary Magnetic Field (IMF) parameters and geomagnetic activity indices are analyzed. The conducted analysis shows that only Auroral Electrojet/Auroral Lower index determines the highest risk for severe environments for surface charging to happen. The presence of a substorm with the southward turning pattern in IMFindicates that the environment can be severe for surface charging to occur but this environment will not depend on whether a substorm was moderate or intense. No clear dependence on IMFis found for risk to a severe environment to occur. Appearances of severe environments for surface charging do not necessarily require high values ofKp(Planetarische Kennziffer) and no storm is needed for such an event to be detected. Among solar wind parameters, solar wind velocityis directly related to the highest risk of severe environments, dependent on thevalue; and number densityis of no importance. Two criteria for severe environment events based on the enhancements of low energy particle fluxes exhibit clearer dependencies on the solar wind and IMF parameters and geomagnetic activity indices with more distinct patterns in their time history.

     
    more » « less
  3. Abstract

    Saturn's magnetosphere has been extensively studied over the past 13 years with the now retired Cassini mission. Periodic modulations in a variety of magnetospheric phenomena have been observed at periods close to those associated with the emission intensity of Saturn kilometric radiation (SKR). Resulting from Rayleigh‐Taylor like plasma instabilities, interchange is believed to be the main plasma transport process in Saturn's inner to middle magnetosphere. Here we examine the organization of equatorially observed interchange events identified based on high‐energy (3–22 keV) H+intensifications by several longitude systems that have been derived from different types of measurements. The main question of interest here is as follows: Do interchange injections undergo periodicities similar to the Saturn kilometric radiation or other magnetospheric phenomena? We find that interchange shows enhanced occurrence rates in the northern longitude systems between 30° and 120°, particularly between 7 and 9 Saturn Radii. However, this modulation is small compared to the organization by local time. Additionally, this organization is weak and inconsistent with previous findings based on data with a limited time span.

     
    more » « less