ABSTRACT This research paper provides a detailed analysis of the properties of hydrogen gas within the universe using hydrogen line radio data analysis, a technique that involves studying the spectral line emitted by neutral hydrogen atoms.The study focuses on the distribution and characteristics of hydrogen gas within the universe and its potential applications for exploring the composition and evolution of planetary systems. The results of the study demonstrate the usefulness of this technique in investigating the properties of hydrogen gas within the universe and highlight the presence of hydrogen gas in numerous solar system objects, including the big planets and their moons, comets, and asteroids. The findings of this study offer important insights into the evolution and composition of the universe, and provide a basis for further research in this field.Overall, this research highlights the fundamental role of hydrogen in shaping the universe and provides a basis for further research in the field of astrophysics. The findings of this study have practical applications in fields such as space exploration and environmental science, as they provide insight into the composition and evolution of celestial objects that impact our planet and its inhabitants. KEYWORDS : Astrophysics; Radio Astronomy; Radio Telescope; Spectral Analysis; Gas Distribution; Neutral Hydrogen; Space Exploration. [1] [2] [1] mailtopritamdutta@aol.com [2] rushilsaraswat@gmail.com

These Earth Energy Budgets (EEBs) came to prominence in 1997 when Kiehl and Trenberth produced their EEB known commonly as KT97. They have regularly come under attack. Primarily they show the Earth emitting 300% more radiation than it receives from the Sun. This energy is being generated out of nothing and violates the 1 st Law of Thermodynamics. They also show the Sun shining on the dark side of the Earth, something that just doesn't happen. All the radiation data in these EEBs, with the exception of Long Wave Down LWD and Long Wave Up LWU infrared IR radiation at the surface, have been divided by 4. This shows the Sun shining equally on all 4 quadrants of the Earth. This has the effect of having the Earth emitting 300% more radiation than it receives from the Sun. This 300% extra radiation is supposedly being generated out of nothing by a greenhouse effect GHE in the atmosphere. It seems apparent that this divide by 4 system is being used as a means of justifying the GHE theory. IR radiation is 100 times less energetic than visible radiation. That means the 322 W/m 2 of IR LWD is the equivalent of 3.22 W/m 2 of visible or Short Wave Down SWD radiation from the Sun. Since it appears these EEBs are being used to calibrate climate models, it has become necessary to review these EEBs and that in turn led to it becoming necessary to generate a new Earth Energy Budget to bring some realism back into them. This paper produces a new Earth Energy budget based on measured data. The Earth receives 1,361 W/m 2 of Short Wave Down SWD solar radiation at the top of atmosphere TOA and 1,361 W/m 2 of Short Wave Up SWU and LWU arrive back at the TOA. 589 W/m 2 of solar radiation is absorbed in the surface and 589 W/m 2 of LWU, latent heat and thermals is emitted by the surface. There is no mystery radiation being generated in the atmosphere and the budget is in balance.

Regions of ECH occurrence in different planetary magnetospheres. Two distinct regions of ECH waves are present in Saturn and Jupiter. ECH waves are seen in the equatorial regions outside the high density plasmasphere / plasma torus and also at intermediate latitude in the magnetospheres, where plasma is confined in a thin disc near centrifugal equator.

The Density-Driven Drag Hypothesis suggests that gravitational interactions are not the result of spacetime curvature, but rather emerge from the influence of spatial density variations on massive objects. This model posits that an increase in spatial density experienced by an object as it approaches another massive object results in a drag effect, which simulates gravitational attraction. This hypothesis reintroduces a separate treatment of space and time, thereby challenging the spacetime framework of relativity. The slingshot effect, frequently observed in celestial mechanics, is interpreted via the layer sorting principle, which explains acceleration in gravitational fields without significant deceleration due to drag. Further research is required to test the viability of this hypothesis.

The electromagnetic coupling between the Galilean satellites at Jupiter and the planetary ionosphere generates an auroral footprint, whose ultimate source is the relative velocity between the moons and the corotating magnetospheric plasma. The footprint can be detected in the infrared L band (3.3-3.6 microns) by the Jovian InfraRed Auroral Mapper (JIRAM) onboard the Juno spacecraft, which can observe the footprint position with high precision. Here, we report the JIRAM data acquired since August 27th 2016 until May 23rd 2022, corresponding to the first 42 orbits of Juno. The dataset is used to compute the average position of the footprint tracks of Io, Europa and Ganymede. The result of the present analysis can help to test the reliability of magnetic field models, to calibrate ground-based observations and to highlight episodes of variability in the footprint positions, which in turn can point out specific conditions of the Jovian magnetospheric environment.

A document by Sverre Holm. Click on the document to view its contents.

A document by Rebecca Ringuette. Click on the document to view its contents.

A document by Michael Lockwood. Click on the document to view its contents.

Recently, many in the space weather community have taken up the cause to advocate for an orphan among our own. It’s an important fight – for ground-based sensor networks. Although ground-based sensors are used across all disciplines of space weather, in terms of long-term support, they have no single clear home in any United States agency or department. This has resulted in an ongoing struggle throughout the community to maintain important space weather sensors and networks.The Promoting Research and Observations of Space Weather to Improve the Forecasting of Tomorrow (PROSWIFT) Act of 2020 (Public Law 116-181) attempts to clarify Federal roles and responsibilities, stating that “… ground-based observations provide crucial data necessary to understand, forecast, and prepare for space weather phenomena”, which it defines as ”radars, lidars, magnetometers, neutron monitors, radio receivers, aurora and airglow imagers, spectrometers, interferometers, and solar observatories.”The data from this list of sensors and arrays support research across the space weather domains, including magnetospheric, ionospheric, and atmospheric science. Networks are run by governmental, academic, and commercial providers, and are used to support a range of end-users, from aviation to the power sector. Given the wide range of applications, it’s not surprising that no single entity has primary custody.In separate sections of PROSWIFT, sustainment of these instruments is assigned to “The Director of the National Science Foundation, the Director of the United States Geological Survey, the Secretary of the Air Force, and, as practicable in support of the Air Force, the Secretary of the Navy” who are directed to “maintain and improve ground-based observations of the Sun, as necessary and advisable”, and also to the National Oceanic and Atmospheric Administration (NOAA), as the civil operational space weather agency that is responsible for maintaining “ground-based… assets to provide observations needed for space weather forecasting, prediction, and warnings”.While PROSWIFT’s clarification of federal responsibilities is welcome, what is highlighted is a problem of the “ownership” of the issue of long-term sustainability of such varied instruments.We can start to unravel the ownership problem by understanding its history. One complication to an easy definition is that ground-based sensor networks support both space weather science and operations. The National Science Foundation (NSF) has a long history of supporting novel instrument development, small arrays of sensors placed for scientific research (fundamental research is the foundation of NSF’s mandate), and mid- and larger-scale facilities. But the needs of science do not necessarily intersect the needs of operations, and neither do their requirements in terms of engineering and support. Operational sensors, in many cases, are entirely different than scientific sensors.Like scientific arrays, operational sensors must provide the “right” data - accurate and relevant – but the delivery of those data must also be timely, consistent, and reliable. In other words, the data must be usable for space weather predictions, forecasts, and alerts. The United States Geological Survey (USGS) is one example of a federal provider of operational ground-based data. The commercial sector, by mandate of PROSWIFT, is another.Whether scientific or operational, ground-based networks need to be supported and maintained long-term to fulfill their missions. It is more expensive to shut down and rebuild an array than to keep it operating, and strategic planning is required to prioritize and balance needs across the space weather enterprise.Those taking up the initiative to support ground-based sensors span the space weather enterprise, reflecting the interdisciplinary and cross-sector need for these data. In addition to a myriad of white papers submitted to the Heliophysics Decadal Survey (e.g., Hartinger et al., and Bhatt et al.) and publications (see Engebretson and Zesta, 2017, and Bain et al., 2023), advisory groups such as the Space Weather Advisory Group (SWAG) and the National Academies Space Weather Roundtable, both put into place by the PROSWIFT Act itself, have taken up the cause. The SWAG, in a public meeting on March 20, 2023 (https://www.weather.gov/swag), called for a “paradigm shift”, agreeing upon a recommendation that there is a need “Provide long-term support for operational ground-based and airborne sensors and networks”.It’s clear that these data are crucial for space weather – both space weather research and operations. With the approach of solar maximum, and the associated rise in space weather hazard, what’s less clear is whether this problem will be solved in time. The community efforts have been effective in raising awareness about the dire situation facing many ground-based sensor networks. What is needed now is a mechanism to maintain these networks long-term, and advocacy for new Federal appropriations to support the organizations that take on the responsibility.

A document by Philip Mulholland. Click on the document to view its contents.

We have identified for the first time an energy-time dispersion of precipitating electron flux in a pulsating aurora patch, ranging from 6.7 keV to 580 keV, through simultaneous in-situ observations of sub-relativistic electrons of microburst precipitations and lower-energy electrons using the LAMP sounding rocket launched from the Poker Flat Research Range in Alaska. Our observations reveal that precipitating electrons with energies of 180-320 keV were observed first, followed by 250-580 keV electrons 0-30 ms later, and finally, after 500-1000 ms, 6.7-14.6 keV electrons were observed. The identified energy-time dispersion is consistent with the theoretical estimation that the relativistic electron microbursts are a high-energy tail of pulsating aurora electrons, which are caused by chorus waves propagating along the field line.

The polar cap can become teardrop shaped through the poleward expansion of the dusk and dawn sectors of the auroral oval, to form what is called horse collar aurora (HCA). The formation of HCA has been linked to dual-lobe reconnection (DLR) where magnetic flux is closed at the dayside magnetopause. A prolonged period of northward IMF is required for the formation of HCA. HCA have previously been identified in UV images captured by the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) instrument on-board the Defense Meteorological Satellite Program (DMSP) spacecraft F16, F17 and F18. Events that have concurrent 630.0 nm all-sky camera (ASC) data from the Redline Geospace Observatory (REGO) Resolute Bay site are now studied in more detail, making use of the higher cadence of the ASC images compared to DMSP/SSUSI. 11 HCA events are studied and classified based on the IMF conditions at the end of the event. Five of the events were found to end via a southward turning of the IMF, two end with positive By dominated IMF and four with negative By dominance. Under positive (negative) By the arcs move duskward (dawnward) in the northern hemisphere with the opposite true in the southern hemisphere. Under a southward turning the arcs move equatorward. One event is of particular interest as it occurred while there was a transpolar arc (TPA) also present. Understanding the evolution of HCA will allow DLR to be studied in more detail.

We built an integrated nonlinear analysis software -INA- designed to study space plasma turbulence and intermittency. The MATLAB programming environment was used for the algorithmic development and implementation of methods for spectral analysis, multiscale fluctuations and multifractal analysis. The performance of INA is demonstrated using magnetic field measurements from the Cluster 3 spacecraft during an inbound pass through the Earth’s magnetosheath region. We show how specific features of the power spectral density (PSD) can be mapped to localised time-frequency regions in the spectrogram representation, and identify multiple intermittent events using the wavelet-based local intermittency measure (LIM). Multiscale probability density functions (PDFs) showed clear departures from Gaussianity, signifying the presence of intermittency. Structure functions (SFs) and rank-ordered multifractal analysis (ROMA) revealed the multifractal nature of the analysed signal. INA is freely distributed as a standalone executable file to any interested user, and provides an integrated, interactive, and user-friendly environment in which one can import a dataset, customize key analysis parameters, apply multiple methods on the same signal and then export high-quality, publication-ready figures. These are only a few of the many distinguishing features of INA.

Solar Energetic Protons (SEPs) have been shown to contribute significantly to the inner zone trapped proton population for energies < 100 MeV and L > 1.3 (Selesnick et al., 2007). The Relativistic Electron Proton Telescope (REPT) on the Van Allen Probes launched 30 August 2012 observed a double-peaked (in L) inner zone population throughout the 7-year lifetime of the mission. It has been proposed that a strong SEP event accompanied by a CME-shock in early March 2012 provided the SEP source for the higher L trapped proton population, which then diffused radially inward to be observed by REPT at L ~ 2. Here, we follow trajectories of SEP protons launched isotropically from a sphere at 7 Re in 15s cadence fields from an LFM-RCM global MHD simulation driven by measured upstream solar wind parameters. The timescale of the interplanetary shock arrival is captured, launching a magnetosonic impulse propagating azimuthally along the dawn and dusk flanks inside the magnetosphere, shown previously to produce SEP trapping. The MHD-test particle simulation uses GOES proton energy spectra to weight the initial radial profile required for the radial diffusion calculation over the following two years. GOES proton measurements also provide a dynamic outer boundary condition for radial diffusion. A direct comparison with REPT measurements 20 months following the trapping event in March 2012 provides good agreement with this novel combination of short-term and long-term evolution of the newly trapped protons.

Models of the high-latitude ionospheric electric field are commonly used to specify the magnetospheric forcing in thermosphere or whole atmosphere models. The use of decades-old models based on spacecraft data is still widespread. Currently the Heelis and Weimer climatology models are most commonly used but it is possible a more recent electric field model could improve forecasting functionality. Modern electric field models, derived from radar data, have been developed to incorporate advances in data availability. It is expected that climatologies based on this larger and up-to-date dataset will better represent the high latitude ionosphere and improve forecasting abilities. An example of two such models, which have been developed using line-of-sight velocity measurements from the Super Dual Auroral Radar Network (SuperDARN) are the Thomas and Shepherd model (TS18), and the Time-Variable Ionospheric Electric Field model (TiVIE). Here we compare the outputs of these electric field models during the September 2017 storm, covering a range of solar wind and interplanetary magnetic field (IMF) conditions. We explore the relationships between the IMF conditions and the model output parameters such as transpolar voltage, the polar cap size and the lower latitude boundary of convection. We find that the electric potential and field parameters from the spacecraft-based models have a significantly higher magnitude than the SuperDARN-based models. We discuss the similarities and differences in topology and magnitude for each model.

The propagating muons deposit their energies in the volume-of-interest (VOI) within the tomographic configurations, and this energy loss directly indicates that there is a difference in terms of the kinetic energy between the incoming muons and the the outgoing muons. In this study, by using the GEANT4 simulations, we first elaborate this energy difference over the nuclear waste barrels that contain cobalt, strontium, caesium, uranium, and plutonium. We show that the deposited energy through these VOIs is not negligible for the initial energy bins. Then, we suggest a correction factor for the image reconstruction codes where the initial kinetic energy of the entering muons is coarsely predicted in accordance with the deflection angle through the hodoscope sections, thereby renormalizing the deflection angle in the bottom hodoscope depending on the intrinsic properties of the corresponding VOIs. This correction factor encompasses useful information about the target volume traversed by the muons since it is related to the intrinsic features of the VOI. Therefore, it might be utilized in order to complement the scattering information as an input to the image reconstruction.

We present in-depth analysis of three southward-moving meso-scale (ion- to magnetohydrodynamic-scale) flux transfer events (FTEs) and subsequent crossing of a reconnecting electron-scale current sheet (ECS), which were observed on 8 December 2015 by the Magnetospheric Multiscale spacecraft near the subsolar magnetopause under southward and duskward magnetosheath magnetic field conditions. Our aims are to understand the generation mechanism of ion-scale magnetic flux ropes (ISFRs) and to reveal causal relationship among magnetic structures of the ECS, electromagnetic energy conversion, and kinetic processes in magnetic reconnection layers. Magnetic field reconstruction methods show that a flux rope with a length of about one ion inertial length existed and was growing in the ECS, supporting the idea that ISFRs can be generated from secondary magnetic reconnection in ECS. Grad-Shafranov reconstruction applied to the three FTEs shows that the FTE flux ropes had axial orientations similar to that of the ISFR in the ECS. This suggests that these FTEs also formed through the same secondary reconnection process, rather than multiple X-line reconnection at spatially separated locations. Four-spacecraft observations of electron pitch-angle distributions and energy conversion rate suggest that the ISFR had three-dimensional magnetic topology and secondary reconnection was patchy or bursty. Previously reported positive and negative values of , with magnitudes much larger than expected for typical magnetopause reconnection, were seen in both magnetosheath and magnetospheric separatrix regions of the ISFR. Many of them coexisted with bi-directional electron beams and intense electric field fluctuations around the electron gyrofrequency, consistent with their origin in separatrix activities.

A NASA sponsored study conducted at John Hopkins University Applied Physics Lab culminated in a community-inspired heliospheric mission concept called the Interstellar Probe (ISP). The ISP’s science goals include understanding our habitable astrosphere by investigating its interactions with the interstellar medium, and determining the structure, composition, and variability of its constituents. A suite of instruments were proposed to achieve these and other science objectives. The instruments include a Lyman-a spectrograph for velocity-resolved measurements of neutral H atoms. The capability to address key components of the ISP’s science objectives by utilizing high spectral resolution Lyman-a measurements are described in this presentation. These findings have been submitted as a community White Paper to the recent Heliophysics decadal survey.

Jupiter’ magnetic field is tilted by ~10º; with respect to the planet’s spin axis, and as a result the Jovian plasma sheet passes over the Galilean satellites at the jovigraphic equator twice per planetary rotation period. The plasma and magnetic field conditions near Ganymede’s magnetosphere therefore change dramatically every ~5 hours, creating a unique magnetosphere-magnetosphere interaction, and on longer time scales as evidenced by orbit-to-orbit variations. In this paper we summarize the typical magnetic field conditions and their variability near Ganymede’s orbit as observed by the Galileo and Juno spacecraft. We fit Juno data from orbit 34, which included the spacecraft’s close Ganymede flyby in June 2021, to a current sheet model and show that the magnetospheric conditions during orbit 34 were very close to the historical average. Our results allow us to infer the upstream conditions at the time of the Juno Ganymede flyby.

This editorial aims to improve awareness of the current best practices in open research, and stimulate discussion on the practical implementation of AGU's data and software policy in key areas of space weather research. We also further aim to encourage authors to take additional steps to ensure clear credit to all contributors to the work, whether that is underlying data, key software, or direct contributions to the manuscript.

Space weather phenomena occur from the Sun to the Earth with damaging impacts on ground-based and space-borne technological infrastructure. The geomagnetic auroral electrojet indices, AU, AL, and AE, have been widely used for monitoring space weather and geomagnetic activities during space storms and substorms. The time series data of solar wind monitored by upstream satellite and ground-based auroral electrojet indices form the input-output system characterizing the dynamic coupling among solar wind, Earth’s magnetosphere, and ionosphere. The data-driven predictions of auroral electrojet indices during geomagnetic storms and substorms face the challenges of capturing the variations of ionospheric electrojet current driven by multiple solar wind variables and are modeled as a coupled complex system with finite and variable memory. The recurrent neural network (RNN) based Long Short-Term Memory (LSTM) machine learning algorithm is well suited to classify, process, and make predictions of the coupled solar wind-magnetosphere-ionosphere system by preserving important information from earlier parts of the coupled time series and carrying it forward. In this study, an RNN-based LSTM model has been built to predict the time series of AE/AL indices with multi-variate solar wind inputs. Both 5-minute and hourly long-term time series data from the NASA OMNI database were used to drive the LSTM model. The coupled time series data are divided into training and testing datasets. The Root-Mean-Square-Error (RMSE) between the predicted and actual AE/AL indices of the testing sets was used to evaluate the roles of the number of layers in the LSTM, memory length of the coupled system, prediction time, and different combinations of solar wind input parameters (magnetic field, velocity, and density). The performance of the LSTM model in predicting AL/AE indices during major geomagnetic storm and substorm events is analyzed. The differences and challenges of applying LSTM to predict 5-min and hourly AE/AL indices are also discussed.

As a rule, the phase velocity of unstable Farley-Buneman waves is found not to exceed the ion-acoustic speed, cs. However, there are known exceptions: under strong electric field conditions, much faster Doppler shifts than expected cs values are sometimes observed with coherent radars at high latitudes. These Doppler shifts are associated with narrow spectral width situations. To find out how much faster than cs these Doppler shifts might be, we developed a proper cs model as a function of altitude and electric field strength based on ion frictional heating and on a recently developed empirical model of the electron temperature under strong electric field conditions. Motivated by the ‘narrow fast’ observations, we then explored how ion drifts in the upper part of the unstable region could add to the Doppler shift observed with coherent radars. While there can be no ion drift contribution for the most unstable modes, and therefore no difference with cs for such modes, under strong electric field conditions, a large ion drift contribution of either sign needs to be added to the Doppler shift of more weakly unstable modes, turning them into ‘fast-‘ or ‘slow-’ narrow spectra. Particularly between 110 and 115 km, the ion drift can alter the Doppler shift of the more weakly unstable modes by several 100 m/s, to the point that their largest phase velocities could approach the ambient E x B drift itself.

Extreme solar particle events (ESPEs) are rare and the most potent known processes of solar eruptive activity. During ESPEs, a vast amount of cosmogenic isotopes (CIs) 10Be, 36Cl and 14C can be produced in the Earth’s atmosphere. Accordingly, CI measurements in natural archives allow us to evaluate particle fluxes during ESPEs. In this work, we present a new method of ESPE fluence (integral flux) reconstruction based on state-of-the-art modeling advances, allowing to fit together different CI data within one model. We represent the ESPE fluence as an ensemble of scaled fluence reconstructions for ground-level enhancement (GLE) events registered by the neutron monitor network since 1956 coupled with satellite and ionospheric measurements data. Reconstructed ESPE fluences appear softer in its spectral shape than earlier estimates, leading to significantly higher estimates of the low-energy (E<100 MeV) fluence. This makes ESPEs even more dangerous for modern technological systems than previously believed. Reconstructed ESPE fluences are fitted with a modified Band function, which eases the use of obtained results in different applications.

The interaction of Io with the co-rotating magnetosphere of Jupiter is known to produce Alfven wings that couple the moon to Jupiter's ionosphere. We present first results from a new numerical model to describe the propagation of these Alfven waves in this system. The model is cast in magnetic dipole coordinates and includes a dense plasma torus that is centered around the centrifugal equator. Results are presented for two density models, showing the dependence of the interaction on the magnetospheric density. Model results are presented for the case when Io is near the centrifugal and magnetic equators as well as when Io is at its northernmost magnetic latitude. The effect of the conductance of Jupiter's ionosphere is considered, showing that a long auroral footprint tail is favored by high Pedersen conductance in the ionosphere. The current patterns in these cases show a U-shaped footprint due to the generation of field-aligned current on the Jupiter-facing and Jupiter-opposed sides of Io, which may be related to the structure in the auroral footprint seen in the infrared by Juno. A model for the development of parallel electric fields is introduced, indicating that the main auroral footprints of Io can generate parallel potentials of up to 100 kV.