44 research outputs found
Coronal disturbances and their effects on the dynamics of the heliosphere
The Sun blows out the solar wind which propagates into the interplanetary medium and forms the heliosphere about 100 AU across. The solar activity causes various types of time-dependent phenomena in the solar wind from long-lived corotating interaction regions to shorter on duration but more extreme events like coronal mass ejections. As these structures propagate outward from the Sun, they evolve and interact with each other and the ambient solar wind. Voyager 1 and 2 provided first unique in-situ measurements of these structures in the outer heliosphere. In particular, Voyager observations in the heliosheath, the outermost region of the heliosphere, showed highly variable plasma flows indicating effects of solar variations extending from the Sun to the heliosphere boundaries. Most surprisingly, Voyager 1 data shows shocks and pressure waves beyond the heliosphere in the interstellar medium. Important questions for the future Interstellar Probe mission are (1) how do the heliosphere boundaries respond to solar variations? (2) how do disturbances evolve in the heliosheath? and (3) how far does the Sun influence extend into the interstellar medium? This talk will review observations and recent modeling efforts demonstrating highly variable and dynamic nature of the global heliosphere in response to disturbances originated in the Sun's atmosphere.https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1229P/abstractPublished versio
The Great Geospace Observatory and Simultaneous Missions of Opportunity
A predictive understanding of the sun to geospace environment is one of the main goals of ILWS. This can only be achieved through a "system-level" approach, meaning long-term, simultaneous, continuous observations across the relevant scales of the magnetosphere and ionosphere/thermosphere (IT). To date such an approach, which must involve simultaneous, multi-scale, global imaging of different geospace regions, has not been carried out for a complete geomagnetic storm. Such imagery, now routine for the Solar community, is of critical scientific importance and captures public imagination. Its absence in geospace studies has limited the growth and impact of geospace science. In this presentation, we discuss a concept called the Great Geospace Observatory, which would involve coordinated geospace imaging through an international effort of multiple, simultaneous Missions of Opportunity. In this way, the cost would be spread among different agencies as well as putting remote sensors in vantage points optimized for each type of imaging. 24/7 auroral imaging from weather satellites on Molniya (or similar) orbits, EUV imaging of the plasmasphere from high-inclination orbits, continuous and global ENA imaging from geosynchronous commercial satellites, and continuous X-ray imaging of the cusp and magnetosheath from a high-altitude dedicated probe would quantitatively track system-level dynamics at through substorms, sawtooth events, steady magnetospheric convection, and storms; studying energy and mass coupling between the solar wind, magnetosphere, and the upper atmosphere. In our minds, The Great Geospace Observatory represents the next strategic step for ILWS and needs to be seriously considered
Parametric analysis of nightside conductance effects on inner magnetospheric dynamics for the 17 April 2002 storm
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95027/1/jgra17945.pd
I enA imaging: seeing the invisible
n what follows, we describe the technique and history of energetic neutral atom (enA) imaging of space plasma and present recent results from international collaborations involving enA imaging experiments as well as results from the imAge mission at earth and the cassini mission at Jupiter and saturn. both imAge and cassini carry ApL-built enA cameras. The henA instrument onboard the imAge mission provides global images of the ring current around the earth and reveals the importance of the electrical coupling between the ring current and the ionosphere. The incA instrument onboard cassini returns enA images from the enormous magnetosphere around saturn, giving unprecedented insight into the dynamics of the hot plasma and its interaction with neutral gas. The review ends with a brief description of enA imaging of the heliospheric boundary and future projects using enA instrumentation
Reimagining Heliophysics: A bold new vision for the next decade and beyond
The field of Heliophysics has a branding problem. We need an answer to the
question: ``What is Heliophysics\?'', the answer to which should clearly and
succinctly defines our science in a compelling way that simultaneously
introduces a sense of wonder and exploration into our science and our missions.
Unfortunately, recent over-reliance on space weather to define our field, as
opposed to simply using it as a practical and relatable example of applied
Heliophysics science, narrows the scope of what solar and space physics is and
diminishes its fundamental importance. Moving forward, our community needs to
be bold and unabashed in our definition of Heliophysics and its big questions.
We should emphasize the general and fundamental importance and excitement of
our science with a new mindset that generalizes and expands the definition of
Heliophysics to include new ``frontiers'' of increasing interest to the
community. Heliophysics should be unbound from its current confinement to the
Sun-Earth connection and expanded to studies of the fundamental nature of space
plasma physics across the solar system and greater cosmos. Finally, we need to
come together as a community to advance our science by envisioning,
prioritizing, and supporting -- with a unified voice -- a set of bold new
missions that target compelling science questions - even if they do not explore
the traditional Sun- and Earth-centric aspects of Heliophysics science. Such
new, large missions to expand the frontiers and scope of Heliophysics science
large missions can be the key to galvanizing the public and policymakers to
support the overall Heliophysics program
Synergies between interstellar dust and heliospheric science with an Interstellar Probe
We discuss the synergies between heliospheric and dust science, the open
science questions, the technological endeavors and programmatic aspects that
are important to maintain or develop in the decade to come. In particular, we
illustrate how we can use interstellar dust in the solar system as a tracer for
the (dynamic) heliosphere properties, and emphasize the fairly unexplored, but
potentially important science question of the role of cosmic dust in
heliospheric and astrospheric physics. We show that an Interstellar Probe
mission with a dedicated dust suite would bring unprecedented advances to
interstellar dust research, and can also contribute-through measuring dust - to
heliospheric science. This can, in particular, be done well if we work in
synergy with other missions inside the solar system, thereby using multiple
vantage points in space to measure the dust as it `rolls' into the heliosphere.
Such synergies between missions inside the solar system and far out are crucial
for disentangling the spatially and temporally varying dust flow. Finally, we
highlight the relevant instrumentation and its suitability for contributing to
finding answers to the research questions.Comment: 18 pages, 7 Figures, 5 Tables. Originally submitted as white paper
for the National Academies Decadal Survey for Solar and Space Physics
2024-203