28 research outputs found
Kamodo’s model-agnostic satellite flythrough: Lowering the utilization barrier for heliophysics model outputs
Heliophysics model outputs are increasingly accessible, but typically are not usable by the majority of the community unless directly collaborating with the relevant model developers. Prohibitive factors include complex file output formats, cryptic metadata, unspecified and often customized coordinate systems, and non-linear coordinate grids. Some pockets of progress exist, giving interfaces to various simulation outputs, but only for a small set of outputs and typically not with open-source, freely available packages. Additionally, the increasing array of tools built upon these sporadic interfaces are typically model-specific. We present Kamodo’s model-agnostic satellite flythrough capabilities as the solution to the utilization barrier for heliophysics model outputs. Developed at the Community Coordinated Modeling Center, these flythrough capabilities are built in Python upon a network of model-agnostic interfaces developed in collaboration with model developers, providing interpolation results the community can trust. Kamodo’s flythrough capabilities present the user with a growing variety of flythrough tools based upon a rapidly expanding library of heliophysics model outputs in several domains, currently including a variety of Ionosphere-Thermosphere-Mesosphere and global magnetosphere model outputs. Each capability is designed to be easily accessible via simplistic model-agnostic syntax, with the entire package freely available in the cloud on Github. Here, we describe the tools developed, include several sample applications for common science questions, demonstrate interoperability with selected packages, and summarize ongoing developments
Space Weather Modeling Capabilities Assessment: Auroral Precipitation and Highâ Latitude Ionospheric Electrodynamics
As part of its International Capabilities Assessment effort, the Community Coordinated Modeling Center initiated several working teams, one of which is focused on the validation of models and methods for determining auroral electrodynamic parameters, including particle precipitation, conductivities, electric fields, neutral density and winds, currents, Joule heating, auroral boundaries, and ion outflow. Auroral electrodynamic properties are needed as input to space weather models, to test and validate the accuracy of physical models, and to provide needed information for space weather customers and researchers. The working team developed a process for validating auroral electrodynamic quantities that begins with the selection of a set of events, followed by construction of ground truth databases using all available data and assimilative data analysis techniques. Using optimized, predefined metrics, the ground truth data for selected events can be used to assess model performance and improvement over time. The availability of global observations and sophisticated data assimilation techniques provides the means to create accurate ground truth databases routinely and accurately.Key PointsA working team has been established to develop a process for validation of auroral precipitation and electrodynamics modelsValidation of auroral electrodynamic parameters requires generation of ground truth data sets for selected eventsCurrent observations and data assimilation techniques continue to improve the accuracy of global auroral electrodynamic specificationPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148365/1/swe20815_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148365/2/swe20815.pd
Absence of extended atmospheres in low-mass star radius-gap planets GJ 9827 b, GJ 9827 d and TOI-1235 b
\textit{Kepler} showed a paucity of planets with radii of 1.5 - 2 around solar mass stars but this radius-gap has not been well
studied for low-mass star planets. Energy-driven escape models like
photoevaporation and core-powered mass-loss predict opposing transition regimes
between rocky and non-rocky planets when compared to models depicting planets
forming in gas-poor environments. Here we present transit observations of three
super-Earth sized planets in the radius-gap around low-mass stars using
high-dispersion InfraRed Doppler (IRD) spectrograph on the Subaru 8.2m
telescope. The planets GJ 9827 b and d orbit around a K6V star and TOI-1235 b
orbits a M0.5 star. We limit any planet-related absorption in the 1083.3 nm
lines of triplet He I by placing an upper-limit on the equivalent width of
14.71 m{\AA}, 18.39 m{\AA}, and 1.44 m{\AA}, for GJ 9827 b (99% confidence), GJ
9827 d (99% confidence) and TOI-1235 b (95% confidence) respectively. Using a
Parker wind model, we cap the mass-loss at 0.25
Gyr and 0.2 Gyr for GJ 9827 b and d,
respectively (99% confidence), and 0.05 Gyr for
TOI-1235 b (95\% confidence) for a representative wind temperature of 5000 K.
Our observed results for the three planets are more consistent with the
predictions from photoevaporation and/or core-powered mass-loss models than the
gas-poor formation models. However, more planets in the radius-gap regime
around the low-mass stars are needed to robustly predict the atmospheric
evolution in planets around low-mass stars.Comment: Accepted for MNRAS. 12 pages, 15 figure
Atmospheric Escape Processes and Planetary Atmospheric Evolution
The habitability of the surface of any planet is determined by a complex
evolution of its interior, surface, and atmosphere. The electromagnetic and
particle radiation of stars drive thermal, chemical and physical alteration of
planetary atmospheres, including escape. Many known extrasolar planets
experience vastly different stellar environments than those in our Solar
system: it is crucial to understand the broad range of processes that lead to
atmospheric escape and evolution under a wide range of conditions if we are to
assess the habitability of worlds around other stars. One problem encountered
between the planetary and the astrophysics communities is a lack of common
language for describing escape processes. Each community has customary
approximations that may be questioned by the other, such as the hypothesis of
H-dominated thermosphere for astrophysicists, or the Sun-like nature of the
stars for planetary scientists. Since exoplanets are becoming one of the main
targets for the detection of life, a common set of definitions and hypotheses
are required. We review the different escape mechanisms proposed for the
evolution of planetary and exoplanetary atmospheres. We propose a common
definition for the different escape mechanisms, and we show the important
parameters to take into account when evaluating the escape at a planet in time.
We show that the paradigm of the magnetic field as an atmospheric shield should
be changed and that recent work on the history of Xenon in Earth's atmosphere
gives an elegant explanation to its enrichment in heavier isotopes: the
so-called Xenon paradox
Cultivating a culture of inclusivity in heliophysics
A large number of heliophysicists from across career levels, institution types, and job titles came together to support a poster at Heliophysics 2050 and the position papers for the 2024 Heliophysics decadal survey titled “Cultivating a Culture of Inclusivity in Heliophysics,” “The Importance of Policies: It’s not just a pipeline problem,” and “Mentorship within Heliophysics.” While writing these position papers, the number of people who privately shared disturbing stories and experiences of bullying and harassment was shocking. The number of people who privately expressed how burned out they were was staggering. The number of people who privately spoke about how they considered leaving the field for their and their family’s health was astounding. And for as much good there is in our community, it is still a toxic environment for many. If we fail to do something now, our field will continue to suffer. While acknowledging the ongoing growth that we as individuals must work toward, we call on our colleagues to join us in working on organizational, group, and personal levels toward a truly inclusive culture, for the wellbeing of our colleagues and the success of our field. This work includes policies, processes, and commitments to promote: accountability for bad actors; financial security through removing the constant anxiety about funding; prioritization of mental health and community through removing constant deadlines and constant last-minute requests; a collaborative culture rather than a hyper-competitive one; and a community where people can thrive as whole persons and do not have to give up a healthy or well-rounded life to succeed
The case for studying other planetary magnetospheres and atmospheres in Heliophysics
Heliophysics is the field that "studies the nature of the Sun, and how it
influences the very nature of space - and, in turn, the atmospheres of
planetary bodies and the technology that exists there." However, NASA's
Heliophysics Division tends to limit study of planetary magnetospheres and
atmospheres to only those of Earth. This leaves exploration and understanding
of space plasma physics at other worlds to the purview of the Planetary Science
and Astrophysics Divisions. This is detrimental to the study of space plasma
physics in general since, although some cross-divisional funding opportunities
do exist, vital elements of space plasma physics can be best addressed by
extending the expertise of Heliophysics scientists to other stellar and
planetary magnetospheres. However, the diverse worlds within the solar system
provide crucial environmental conditions that are not replicated at Earth but
can provide deep insight into fundamental space plasma physics processes.
Studying planetary systems with Heliophysics objectives, comprehensive
instrumentation, and new grant opportunities for analysis and modeling would
enable a novel understanding of fundamental and universal processes of space
plasma physics. As such, the Heliophysics community should be prepared to
consider, prioritize, and fund dedicated Heliophysics efforts to planetary
targets to specifically study space physics and aeronomy objectives
Effects of ionospheric oxygen on magnetospheric structure and dynamics
Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.During geomagnetically active times, ionospheric O + can contribute a significant fraction of the magnetospheric mass and energy densities. The global response of Earth's magnetosphere to the presence of ionospheric oxygen is still largely unknown and impossible to examine fully with in situ , single point satellite measurements. Global magnetohydrodynamic (MHD) models provide a picture of this large-scale response to ionospheric outflow. The goal of this dissertation is to examine the behavior and effects of outflowing oxygen in a multi-fluid MHD model by determining (1) how O + outflow from different regions of the ionosphere contributes to plasma sheet populations and (2) the effect of these oxygen populations on convection and global magnetospheric structure. I implement two empirical outflow models at the inner boundary of the recently-developed Multi-Fluid Lyon-Fedder-Mobarry MHD code and examine the response of the model to various outflow conditions. A model based on data from the Akebono spacecraft (Ebihara et al. , 2006) provides a low-energy polar and auroral region outflow, whereas a model based on data from the FAST spacecraft (Strangeway et al. , 2005) provides higher-energy outflow confined to the auroral regions. Using the Akebono model outflow, I show that both centrifugal acceleration and pressure gradients accelerate thermal O+ along the magnetic field into the plasma sheet and downtail into the solar wind. I examine O+ and H + plasma sheet populations for different outflow and solar wind conditions. To account for observed densities, nightside outflows must be augmented by polar wind, cusp outflows, or both. O+ outflow in general, and nightside outflow in particular, loads the plasma sheet with O + , inflating the plasma sheet, increasing the width of the tail and distance to the tail x-line, and reducing cross polar cap potential (CPCP). These effects are shown to relate to the width of the magnetosheath, indicating that the reduction in CPCP may be due to changes in the bow shock and magnetosheath that divert the solar wind around the magnetosphere. Finally, I show that during a realistic substorm simulation, the timing and strength of substorms are changed by a global O + outflow.2031-01-0