Atmospheric temperature and relative humidity profiles are fundamental for atmospheric research such as numerical weather prediction and climate change assessment. Hyperspectral satellite data contain a wealth of relevant information and have been used in many algorithms (e.g. regression-based methods) to retrieve these profiles. Deep Learning or Deep Neural Network (DNN) is capable of finding complex relationships (functions) between pairs of input and output variables by assembling many simple non-linear modules together and learning the parameters therein from large amounts of observations. DNN has been successfully applied in many fields (such as image classification, object detection, language translation). In this study, we explored the potential of retrieving atmospheric profiles from hyperspectral satellite radiation data using DNN. The requirement for applying the DNN technique is satisfied with large amount of hyperspectral radiance data provided by United States Suomi National Polar (NPP) Cross-track Infrared Sounder (CrIS) and the reanalyzed atmospheric profiles data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF). The proposed DNN consists of two consecutive parts. In the first part, the first 1245 bands of the NPP CrIS hyperspectral radiance data (648.75 to 2555 cm-1) are compressed into a 300-element vector representing their key features by stacked AutoEncoders. Then, in the second part, the multi-layer Self-Normalizing Neural Network (SNN) is used to map the compressed vector (of 300 elements) into 55-layer temperature and relative humidity profiles. The DNN trainable variables are optimized by minimizing the difference of its predictions and the matched ECMWF temperature and humidity profiles (53230 samples). Finally, the DNN retrieved atmospheric temperature and relative humidity profiles and those provided by the NOAA Unique Combined Atmospheric Processing System (NUCAPS, the official retrieval products for CrIS) are compared with the matched radiosonde observations at one location.

We have developed a suite of computer-based interactive educational activities for introductory sedimentology and stratigraphy courses, called SedEdu. Specifically, SedEdu is a free and open-source Python framework through which any contributor can easily and seamlessly integrate their own “module” into the suite for distribution. In this way, SedEdu is a community-built tool written by sedimentology and stratigraphy educators for sedimentology and stratigraphy educators. The so-called modules are coupled with “activities” that guide students through a concept, incrementally introducing components of the subject, and testing for understanding and retention throughout the activity. For example, one module (“rivers2stratigraphy”) illustrates the concept of the construction of fluvial stratigraphy through a laterally migrating river that leaves behind a channel-sand body, which is subsided into a stratigraphic profile. The module allows students to modulate system properties like water discharge, subsidence rate, and avulsion timescale, and observe changes in the developed stratigraphic record. At one point during an activity accompanying this module, students are guided to decrease the basin subsidence rate, and then to measure (using in-activity tools) the change in sand-body stacking patterns before and after the subsidence change. A small-scale test was conducted, wherein the SedEdu rivers2stratigraphy module was used as a curriculum component. In the test, one section of an undergraduate sedimentology and stratigraphy class was taught using traditional lecture materials, and the other used the module on student computers. The efficacy of this style of technology-enabled active learning was tested through a multivariate assessment of student’s understanding of fluvial stratigraphy construction.

The release of freshwater into the North Atlantic by glacial Lake Agassiz towards the end of the last glacial period is hypothesized to have triggered the Younger Dryas (Y.D.) cold event of 12.9 -11.7 ka ago. It is thought that the influx of freshwater into the Atlantic weakened meridional overturning circulation, impeding heat transport to the northern latitudes. A subject of debate at present is how the freshwater released from Lake Agassiz was routed to the ocean. One suggestion is that the retreat of the Laurentide Ice Sheet (LIS) from the Lake Superior Basin allowed water from Lake Agassiz, which was flowing south to the Gulf of Mexico, to be redirected eastward via the St Lawrence River to reach the Atlantic. Reported surface exposure ages indicate that the St Lawrence River route became available between 13.0 and 12.7 ka ago, timing that is coincident with the onset of the Y.D. event. An alternative route for the drainage from Lake Agassiz is that it flowed northwestwards to the Arctic Ocean via the Mackenzie River in northwest Canada. This suggestion has been affirmed by some modeling studies that found that meridional overturning in the North Atlantic would have been weakened more significantly if freshwater was introduced via the Arctic. A flow path, and deposits that have been identified on the Canadian Arctic Coastal Plain have yielded luminescence ages indicating that a major flood event occurred sometime between 13.0 and 11.7 ka ago. From that age range, however, it is not possible to ascertain if the flood triggered the Y.D. Thus, in this study, in order to determine a more precise timeline for the northwestward drainage of Lake Agassiz, we collected postglacial eolian dune sands from northeast Alberta, Canada, an area through which water from Lake Agassiz would have had to pass in order to reach the Arctic Ocean. The dune sands were sourced by wind from sediments left behind following the drainage of glacial Lake McConnell which had also been dammed in the region by the LIS. Preliminary luminescence ages obtained from the eolian sands suggest that northeast Alberta was free of both ice and glacial lakes by 13.5-12.5 ka ago. This indicates that flow from Lake Agassiz via the Mackenzie River cannot be excluded as a trigger for the Y.D. since the northwestward drainage path appears to have also been available at the start of the event.

The origin of Kiruna-type magnetite-apatite deposits, which are thought to form by magmatic and/or hydrothermal processes, has recently come under renewed scrutiny. Geological and geochemical studies of volcanic-hosted magnetite deposits that include magnetite lava flows and ash layers at El Laco, a volcano in the Central Volcanic Zone, northern Chile, suggest a formation by eruptive emplacement of an iron oxide-rich melt. The generation of such exotic high density, low viscosity melts by dissociation from an andesitic host magma contaminated by shallow crustal sediments has only recently been shown experimentally. The dynamics of volcanic emplacement have remained enigmatic because the high density of iron-rich melts seems to negate their eruption potential. Yet, observations of ubiquitous vesiculation, degassing structures, and steam-heated alteration provide important clues that volatiles had a pivotal role in the volcanic emplacement. Here, we posit a scenario in which an iron-rich immiscible liquid gravitationally separates from its andesitic parent magma in a shallow magma reservoir and subsequently rises as a bubbly suspension along volcano-tectonic faults extending to the flanks of the edifice. We test this hypothesis through numerical models that capture both the deformation of the volcanic edifice as well as the melt transport within. Preliminary results indicate that separation of a low-viscosity, iron- and volatile-rich melt from a silicic magma within a reasonable time is possible only if an interconnected melt drainage networks forms at the granular scale. Results further suggest that magma reservoir deflation and/or minor local extension combined with the topographic load of the edifice may explain normal faults connecting the magma reservoir with magnetite flow locations on the volcano flanks. Finally, our models show that hydrostatically driven flow of iron-rich melts into these faults at depth may trigger volatile exsolution and bubble expansion to provide sufficient driving force for an eruptive emplacement. Although the case for such magmatic ore formation is perhaps strongest at El Laco, evidence from other localities suggests that similar processes have been at work. The new insights derived from our models may, therefore, apply more generally to Kiruna-type deposits elsewhere.

The formation of crystal clusters may influence the mechanical behaviour of magmas. However whether clusters form largely from physical contact in a mobile state during sedimentation and stirring, or require residence in a crystal mush is not well understood. We use discrete-element fluid dynamics numerical experiments to illuminate the potential for clustering from both sedimentation and open-system mixing in a model olivine basalt reservoir for three different initial solid volume fractions. Crystal clustering is quantified using both bulk measures of clustering such as the R index and Ripley’s L(r) and g(r) functions and with a variable scale technique called Voronoi tessellations, which also provide orientation data. Probability density functions for the likelihood of crystal clustering under freely circulating conditions indicates that there is nearly an equal likelihood for clustering and non-clustered textures in natural examples. A crystal cargo in igneous rock suites exhibiting a dominance of crystal clusters may be largely sampling magmatic materials formed in a crystal mush.

To date, actively flowing lava has only been observed on Earth and on Jupiter’s moon Io. This lack of observation means that for the vast majority of volcanic systems in the Solar System, solidified lava-flow morphologies are used to infer important information about eruption and emplacement parameters. These include: lava supply rate, lava composition, lava rheology, and determination of laminar or turbulent emplacement regimes. Commonly used models that relate simple lava flow morphologic properties (e.g., width, thickness, length) to emplacement characteristics are based on assumptions that are readily misinterpreted. For example, the simplifying assumption of fully turbulent lava flow allows for a thermally mixed flow interior, but ignores the lava properties that naturally work to suppress full turbulence (such as thermal boundary layers encasing active lava flows, and a temperature-dependent lava rheology). However, full turbulence in silicate lava flows erupted into environments that have temperatures lower than the lava solidification temperature requires a rare combination of characteristics. We model Bingham Plastic, Newtonian, and Herschel-Bulkley fluids in rectangular channels, tubes, and sheets with computational fluid dynamics (COMSOL) software to obtain flow solutions and general flow rate equations and compare them to field measurements of volcanic velocity and flow rates. We present these as more realistic alternatives to older simpler rate-from-morphology models. We find that several lava rheology properties work together to delay the onset of turbulence as compared to isothermal Newtonian materials, and that while turbulent lavas flows certainly exist, they are not as prevalent as the published literature might indicate. Results obtained from models that assume full turbulence in silicate flows on the terrestrial planets should therefore be interpreted cautiously.

To prevent serious problems occurring in abandoned mines such as ground subsidence, it is commonly carried out to fill cavities with some materials. During or after the cavity-filling process, we need to monitor distribution of filling materials in abandoned mines. Various geophysical methods, such as microgravity, electrical resistivity, ground penetrating radar, and seismic methods, have been used to describe abandoned mines themselves or to monitor distribution of filling materials. Microgravity, electrical resistivity, ground penetrating radar, and microseismic methods can be used to detect cavities, but may have some limitation in monitoring material distributions. In this study, we apply the seismic reflection method to image distribution of filling materials in near-surface abandoned mines. As the imaging methods, we use full waveform inversion and reverse time migration. In addition, we apply seismic interferometry to obtain better results. The full waveform inversion and reverse time migration methods are applied to four models which can mainly appear in abandoned mines. Through numerical examples, we investigate feasibility of seismic reflection method for describing filling material distribution in abandoned mine. Acknowledgements This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2017R1A2B4002031) and by the project funded by the Ministry of Oceans and Fisheries, Korea (D11603317H480000112).

There have been numerous calls to promote reproducible research. This growing awareness coincides with major advances in data/code sharing technologies. Yet authors, journals, institutions, and funders still need to act to advance more reproducible research. Here, we suggest to view reproducibility as a continuum that includes the 1) availability of data, models, code, and directions to use the digital artifacts, 2) replication of results, and 3) reproducibility of findings. We present a simple survey tool to assess where a peer-reviewed journal article lies on the continuum. We use the tool to assess 360 random sampled articles of the 1,989 articles published in 2017 in six well-regarded hydrology and water resources journals. 49% of sampled articles had some materials available online, but just 5.6% made available all the data, models, code, and directions. For 1.6% of articles, we generated results that replicated some or all of the published results. Assessments took 5 to 14 minutes per article to determine the availability of digital artifacts and 25 to 86 minutes to replicate results (25-75% range). The availability of data, models, code, and directions differed by journal and journal policy towards data availability. From the 360 article sample, we estimate that 0.6% to 6.8% of all articles published in the six journals in 2017 can be replicated using their published artifacts (95% confidence interval). These results suggest several practices to improve the reproducibility of published research. First, authors should provide directions to use their data, models, and code in addition to the digital artifacts. Second, on author submission, journals should use a tool like ours to assess the submission’s position on the reproducibility continuum. Third, journals should formulate policies that require authors to state the intended reproducibility of their work and place relevant information in an easy-to-find article location. Fourth, journals, institutions, and funders should highlight work whose digital artifacts, results, and findings are available, replicable, and reproducible.

Air composition of the Lewis-Clark Valley (LCV) was studied over a two-year period to investigate the effects of a local pulp paper mill on ambient air and to assess potential health risk to the community. Lewiston, Idaho and Clarkston, Washington are twin cities in the Snake River Valley bordering North-Central Idaho and Southeastern Washington, with a population of over 50,000 including the surrounding areas. The paper mill is located in North Lewiston and releases malodorous sulfur air pollutants in the LCV. The neighboring Nez Perce Tribe has conducted a couple of air studies, in 2006-2007 and the summer of 2016-17, but to date no longer term study has taken place. Our current study utilized active air sampling via sorbent tubes followed by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS) analysis to measure over 50 volatile organic compounds, hazardous air pollutants, and sulfides in ambient air (adapted from EPA Method TO-17). Seasonal, diurnal, and spatial variations in air composition were explored. In addition, monthly averaged passive air samples were collected for comparison at nearby urban areas – Boise, ID, Coeur d’Alene, ID, and Spokane, WA in 2018. In the LCV, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) were the primary sulfur compounds detected, with concentrations highest adjacent to the paper mill. However, concentrations varied considerably depending on time of day, season, location and meteorology. Seasonal observations include DMS, benzene and chloroform peaking in the summer months, while DMDS peaks in the winter. Diurnal trends show DMS and chloroform with higher values during the morning hours than later in the day. The long-term monthly samples show benzene decreasing from winter to spring, with LCV levels comparable to Coeur d’Alene and Spokane, and Boise slightly higher. In most cases, benzene levels exceed those recommended for ambient air in the state of Idaho. Sources and potential health implications will be discussed.

The Lithium Nevada Corp. Thacker Pass Project has a measured resource of 242M tonnes at 0.29% Li (~0.7M tonnes Li). The deposit is the southernmost of five known lenses hosted within intracaldera tuffaceous sediments along the west side of the McDermitt caldera, which formed by eruption of 16.4 Ma peralkaline-metaluminous tuff. Analyses of 9880 core samples (~1.5-m thick) give a mean of ~ 2500 ppm Li, with some >8800 ppm. Entire sedimentary sections in the southern and western parts of the caldera basin have high Li (1500+ ppm). Pre-caldera rocks, the McDermitt Tuff, late caldera volcanics, and unaltered tuffaceous sediments have relatively low Li (5 -140 ppm). Sediment deposition was mainly subaqueous in the closed caldera basin. Li-rich fill may have been deposited from airborne sources. Claystone comprises most of the Thacker Pass deposit and dominates Li-rich intervals. The rest is mostly feldspar-rich ash. X-ray diffraction (XRD) data from six core holes across the deposit show consistent lateral mineral zoning. A Li-rich zone (mean >4,000 ppm) mainly contains illitic clay and underlies a zone of lower Li with smectite + analcime. Based on XRD peak locations and chemistry, the closest analogs to the illitic clay are Li micas (e.g. tainiolite). Montmorillonitic clay and a basal silicified zone underlie the illitic zone. Some transitional rock of mixed-layer clay between the illite and smectite zones also has high Li. All clay has similar optical properties but SEM images show illite forms tiny hexagonal plates and smectite has no resolvable crystallinity. Calcite, albite, K-feldspar, and quartz occur in all zones, dolomite and fluorite near the top of the illite zone, and pyrite and bitumen in unoxidized rock. The Li-rich zone has relatively high K, Rb, Mo, As, and Sb. Secondary Kspar in the Li-rich zone gave an 40Ar/39Ar age of 14.87±0.05 Ma. No origin fully explains known characteristics. The presence of illite suggests a moderate temperature hydrothermal system. Release of Li from tuffaceous sediments and transport by alkaline groundwater are consistent with most mineralogy (characteristic of closed hydrologic system diagenesis) and with the Kspar date that long postdates caldera magmatism. Release of 10 ppm Li from the likely 50-200 km3 of intracaldera sediments would contribute ~1-4M tonnes Li.

Community science is a collaboration between scientists and communities including their citizens and their leaders. In this collaboration, the scientists and communities together determine the questions to be studied, the approaches to be taken, and the interpretation of the results. Such a collaboration requires a foundation of scientific literacy within the community to enable both individuals and the community as whole to access the needed scientific understanding and to participate in the scientific process. It also requires that scientists and educators learn about the knowledge, values, norms, and priorities of the communities in which they are working—a kind of scientific community literacy. The EarthConnections Alliance supports the engagement of educational institutions and programs in community science while building community science literacy and scientific community literacy. The EarthConnections Alliance is formed of regional groups that are invested in linking geoscience learning and community service across grade levels within their communities as well as program partners who have expertise needed to create these learning opportunities. All members share a vision of creating learning pathways with four critical elements: 1) they connect opportunities to learn geoscience with opportunities to use this knowledge in service to the local community; 2) they link geoscience learning opportunities and learners across grade levels; 3) they use signposting and mentoring to guide and support students; and 4) they lead to local employment opportunities and geoscience-related careers. Initial funding for EarthConnections explored the creation of regional pathways in diverse sites across the country, the development of strategies and tools for supporting pathway development, and mechanisms for sharing resources and expertise within the Alliance. Over 125 individuals and groups are now engaged in this effort. Further information is available on the EarthConnections website: serc.carleton.edu/EarthConnections.html.

First-arrival traveltime tomography (FATT) has been one of the commanding tomographic approaches for long wavelength velocity model building. Nowadays, FATT models are often used as initial models for more resolving imaging methods such as full-waveform inversion (FWI). In this context, improving the accuracy of FATT model is crucial to mitigate the nonlinearity of FWI. In spite of the widespread use of FATT at all scales (from near surface to global scale), it suffers from ill-posedness in terms of non-uniqueness of the solution due to the deficient information carried out by the sole traveltime attribute. We promote the use of the traveltime perturbation with respect to the source/receiver positions (horizontal component of the slowness vector or slope) as a supplement to the first-arrival traveltime (Tavakoli et al., 2018). For multi-component controlled-source experiments, we can generally take advantage of the fine source sampling to measure slopes by tracking local coherency over few neighboring traces in addition to traveltimes in common-receiver gathers, while slopes at the receiver position may be estimated by polarization analysis. The information of differential nature carried out by slopes yields a higher order sensitivity with respect to the subsurface parameters. We implement our first-arrival slope+traveltime (FASTT) tomography with eikonal solver and the matrix-free adjoint-state method, as previously proposed by Taillandier et al.(2009) for FATT. We illustrate the resolution power of FASTT relatively to FATT for coarse ocean bottom seismometer (OBS) acquisitions using two benchmarks based upon the EAGE/SEG Overthrust model at the exploration scale and a synthetic model of the eastern-Nankai subduction zone at the deep crustal scale (Górszczyk et al., 2018), then assess the quality of the tomographic models as initial models for FWI. We finally present an application to real OBS data collected during the SFJ experiment in the eastern Nankai Trough (Tokai area).

While about 17% of the adult population have significant hearing loss, we remain under-represented within academia outside of the field of Deaf Studies. One primary contributor to the leaky pipeline is lack of mentorship due to the difficulty of deaf and hard of hearing academics in recognizing one another. Hearing loss among non-signers is seldom obvious. Consequently, non-signing deaf and hard of hearing academics at predominantly hearing institutions often remain isolated without guidance on how to manage the myriad of communication challenges facing academics, such as teaching, leading group meetings, addressing questions at conferences, participating in discussions at professional meetings, and serving on grant proposal panels. Adequate solutions are often not available from our hearing health care providers nor from disability services offices, which are mandated and designed to serve undergraduate students. However, the success of all academics depends on mastering these different communication challenges. To fill the mentoring gap, we have started a blog by and for academics at all career stages with some degree of hearing loss called, “The Mind Hears”. This title derives from the Victor Hugo quote “What matters deafness of the ear when the mind hears, the one true deafness, the incurability deafness is that of the mind.” The goals of the blog are: To provide a forum for crowd-sourcing ways to minimize our challenges and share strategies for thriving in academia with hearing loss. To foster a network of deaf and hard of hearing academics who promote hearing inclusive strategies at universities. Through this blog we hope to reach deaf and hard of hearing academics all around the world, and thus reduce isolation in our community and build a community toolbox of resources and ideas. Hearing loss is variable and can affect us in many and different ways – but through this shared blog we hope to provide something of value to all of those who visit and contribute to our discussions.

In Greek mythology, Cassandra was cursed with a prophetic knowledge of the future that no one would believe. The premise of this mythological prophet is also an apt description of the challenge facing scientists in communicating climate change. Central to addressing this challenge is the ability to examine, interpret and understand the individual scaffolding that underlies people's perception of climate change. Human-centered design incorporates a deep assessment of human needs in the design of systems and services, providing an alternative lens to engage in action towards climate change. Over the course of three separate design classes, attracting a diverse array of students from undergraduate to PhD to professional degrees, from engineers to humanists, we have explored the intersection of design education and climate change communication. In Design for a Habitable Planet, students conducted broad unstructured interviews to populate a matrix of beliefs and experiences around climate change, allowing them to bridge a perceived empathy gap. Their subjects included local fisherman, who are experiencing climate change but are ideologically opposed to the concept, and Alaska Native students who are experiencing climate change as part of a larger portfolio of challenges facing their communities. Leveraging theories from behavioral psychology, students then developed and prototyped an array of climate action campaigns, using an array of mediums from Snapchat filters to crowd-sourced climate haiku on beer labels. A unique outcome of the design process was a set of strategies intended to engage voices from all corners of the climate change debate and in turn inspire action. In Design of Data, students were challenged to design a data journalism piece highlighting positive action to address climate change. Students struggled with their pre-conceived negative bias around climate change, but after an examination of their own communities, what emerged were eight compelling stories daylighting positive and collective action to address global change. Ultimately, through our classroom experiments integrating design, behavioral psychology and climate change communication, students have not only learned to engage across differences, but we have developed a first glimpse of the power of design to inspire novel strategies to incite positive action to address climate change.

Brazil is one of the richest countries in water resources and is currently the second largest global supplier of food and agricultural products. Furthermore, more than 70% of Brazilian energy comes from hydropower. Therefore, to ensure water availability for future generations it is necessary to consider the Nexus thinking (water, food, energy, ecosystem service, and social aspects integrated) in the country. However, few studies have been developed considering the Nexus thinking in Brazil. Understanding the interconnected risks and vulnerability to these sectors under climatic change conditions is crucial for the development of sustainable resources management plans and for mitigating competition among them. Here, we assess the Food-Energy-Water Nexus considering climate and land cover and land use changes (LCLUC) scenarios in the São Francisco river basin. This basin is the third largest basin in Brazil and supplies water to approximately 14 million inhabitants, with the Metropolitan Region of Belo Horizonte being the most populous area. The São Francisco river has been used for water supply, irrigation, agriculture and transportation by waterways, but its preponderant use is for hydroelectric power generation. However, this basin has been suffering from LCLUC and drought that has plagued the region since 2012. In addition, part of the river flow has been diverted due to the transposition of the São Francisco river to supply water to the semi-arid region of Brazil. We will calibrate and evaluate the Soil and Water Assessment Tool (SWAT) using hydrometeorological data from 1972 to 2017. We will also use LCLUC scenarios from the OTIMIZAGRO model and regional climate change models (HadGEM2-ES and MIROC5, RCP 4.5 and 8.5). Then, we will compute the demands of water by different sectors and integrate water availability and demand to reach an optimal water use based on the Nexus thinking. Our results will provide decision-makers with information regarding the risks and trade-offs and will support water resources management decisions in order to allocate scarce water resources toward food or energy.

The concept of an Interstellar Probe (ISP) offers an intriguing combination of scientific break-throughs in several disciplines. These include a global view of our heliosphere, unperturbed sampling of the interstellar medium, discoveries of Kuiper Belt Objects, and many others. The current mission concept of the ISP aims at reaching a distance of 1000 au away from the Sun within this century, far beyond the heliopause at roughly 100-200 au. In this presentation, we investigate basic requirements for an Energetic Neutral Atom (ENA) instrument onboard the ISP for the energy range between 10 eV and 5 keV. An ENA is produced when a fast ion exchanges its charge with an ambient neutral atom. The resulting ENA leaves the source region on a straight trajectory, no longer influenced by electromagnetic fields. This allows an ENA camera to image the ion distribution of remote plasma regions. We calculate the energy spectrum of heliospheric ENAs an observer would see from a given vantage point inside or outside the heliopause. Since the global shape of the heliosphere is unknown yet, we use two analytical models to derive proton flowlines for two different heliospheric shapes: the Parker model [Parker 1961] modified with a termination shock and the analytical representation of a full MHD model [Röken et al. 2015, Kleimann et al. 2017]. The ENA intensity then is the line-of-sight integral of proton density times the local density of neutral hydrogen times the charge-exchange cross-section. We disregard any other neutral species inside the heliosphere and we only consider protons as source for ENAs. The proton populations included are the supersonic solar wind and pickup ions inside the termination shock and the shocked solar wind and pickup ions between termination shock and heliopause. The calculated ENA intensities are first compared to the globally distributed ENA flux measured by the Interstellar Boundary Explorer and Cassini in the inner solar system in the energy range from 10 eV to 55 keV. We then proceed to calculate the ENA intensity as seen by an observer at other positions near or beyond the heliopause. These predictions can serve as a rough guideline for the mission concept of ISP: which trajectory offers the most interesting view on the heliosphere in ENAs and which technical requirements should a low-energy ENA imager meet?

We investigate electron whistler wave activity in the flux pile-up region of an asymmetric reconnection event at the magnetopause. The ~140Hz waves are right-hand polarized with a wave normal angle of ~20 degrees and track the magnetic field strength, consistent with electron whistler waves. Poynting flux direction indicates that the waves were generated at the reconnection site. The waves modulated the flux of 500eV electrons propagating parallel and anti-parallel to the magnetic field, as observed by EDI. Only two of four MMS spacecraft observe similar wave activity, suggesting that the waves are isolated within a narrow flux tube. While it is not possible to use the wave telescope technique, current density produced by 500eV electrons provides a means of estimating the parallel wave vector, k, from a single spacecraft. In addition, we fit the FPI electron parallel energy distribution with a kappa function then use Liouville mapping with 500eV EDI electrons to determine the parallel wave potential, 𝝓, and electric field, E. Combining this with the wave normal angle and Poynting flux direction provides an estimate for the perpendicular components of k and E.

The Earth’s crystalline inner core (IC) solidifies from the liquid Fe alloy of the outer core (OC), which releases latent heat and light elements sustaining the geodynamo. Variability in solidification regime at the inner core boundary (ICB) may result in compositional and thermal multi-scale mosaic of the IC surface and dissimilarity of its hemispheres. Both the mosaic and hemisphericity are poorly constrained, not least due to a lack of available sampling by short-period reflected waves. Measured amplitude ratio of seismic phases of PKiKP and PcP reflected, respectively, off the inner and outer boundary of the liquid core, yields direct estimate of the ICB density jump. This parameter is capable of constraining the inner – outer core compositional difference and latent energy release, but is not well known (0.2–1.2 g/cub cm), and its distribution is obscure. Travel time measurements of PKiKP and PcP waveforms can be useful in terms of getting an insight into fine structure of ICB and its topography. We analyse a new representative sample of pre-critical PKiKP/PcP differential travel times and amplitude ratios that probes the core’s spots under Southeastern Asia and South America . We observe a statistically significant systematic bias between the measurements collected in western and eastern hemispheres, and carefully examine its origin. Separating the effects of core-mantle boundary (CMB) and ICB on the measured differentials is particularly challenging and we acknowledge that a whole class of physically valid models involving D” heterogeneities and lateral variation in lower mantle attenuation can be addressed to account for the observed hemisphericity. However, we find that variance in PKiKP-PcP differential travel times measured above the epicentral distance of 16 degrees is essentially due to mantle heterogeneities. Analysis of data below this distance indicates the ICB density jump under Southeastern Asia can be about 0.3 g/cub. cm, which is three times as small as under South America where also the thickness of the liquid core can be by 1-3 km in excess of the one in the East. The findings are interpretable as evidence for IC hemispherical asymmetry whereby crystallization dominates in the West and melting in the East (and not vice versa) or in terms of two disconnected mosaic patches with contrasting properties.