Accurate isotope compositions of nanoparticles in planetary materials provide critical constraints on the evolution of the early solar system. Atom probe tomography (APT) can analyze isotopes in situ with the highest spatial resolution, making it ideal for nanoscale planetary materials. However, significant deviations between isotope ratios determined using APT and a traditional mass spectrometer have hindered the wide application of APT in isotope analysis. Here, we propose that these isotope ratio discrepancies arise from different uncounted rates of the isotopes in APT analysis. Theoretical assessment indicates that such discrepancies can be corrected using a suite of reference materials. Iron isotope analyses of Fe-Mn-Ni steels and meteoritic irons using APT and a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS) confirm a strong linear correlation between the two data sets, supporting the establishment of 56Fe/54Fe and 57Fe/54Fe calibration curves for APT data correction. The calibration curves were subsequently validated using four meteoritic irons with known Fe isotope ratios. Combining all of the errors, our corrected APT results achieve a 2σ uncertainty of <0.15‰ for δ56Fe. This precision demonstrates that our calibrated APT protocol enables accurate isotope determination, unlocking the potential of APT for precise isotope analysis of nanoscale planetary materials.

Auroral kilometric radiation (AKR), Earth's strongest radio emission, has long been associated with discrete auroras and electrons near a few kilo-electron volt (keV) range. However, auroras also occur in diffuse forms with broader electron energies, raising the question of why AKR has not been observed above diffuse auroras or linked to electrons outside the kilo-electron volt population. Comprehensive AKR source distributions have remained elusive because of observational limitations, and their local-time coverage remains largely unknown. Using spacecraft measurements, we identify a "radio oval" above the optical auroral oval, spanning the full local-time range, where AKR is emitted over both discrete and diffuse auroras. The AKR source electrons display diverse precipitation features, including monoenergetic (peak flux at 3.82 kilo-electron volts), broadband (1.34 kilo-electron volts), low-energy (0.47 kilo-electron volts), and diffuse types (>1 kilo-electron volt). These results reveal that the cyclotron maser instability-the mechanism driving AKR-can arise in diverse plasma environments, broadening our understanding of both AKR generation and auroral complexity.

A novel X-ray free electron laser (XFEL) diffraction setup for use with diamond anvil cells (DACs) at the Linac Coherent Light Source (LCLS) is described. The new diamond window at the Matter at Extreme Conditions (MEC) instrument allows hard X-ray experiments on DACs to be performed in air. The platform is described along with alignment and calibration procedures, and details of the X-ray beam and diagnostics. Example data are presented, including a reversible XFEL-induced phase transition in CsPbI3. The DAC setup was commissioned at MEC, but is applicable to most LCLS instruments where the unique pulse structures available at LCLS offer access to new ultrafast experimental techniques at high pressure.

Methane measurements, particularly of natural sources, need to be expanded considerably.

Abstract Improvements in software, parallel computing, global data sets, and laboratory flow‐laws help to develop the global Earth5 thin‐shell finite‐element model of Bird et al. (2008, https://doi.org/10.1029/2007jb005460 ) into a benchmark study. All experiments confirm that modeled faults (other than megathrusts) have low effective friction of 0.085 ± 0.034. The average down‐dip integral of shear traction on subduction megathrusts is 1.3 ± 0.2 × 10 12 N/m. In plate interiors the dislocation‐creep flow‐law for continental crust is about twice as strong as granodiorite; close to diorite. Upper‐mantle creep strength is close to olivine‐rich peridotite in both oceanic lithosphere and continents. “Byerlee's law” friction of 0.85 applies between active faults in both oceanic lithosphere and stable continents. Computed net slab‐pull on subducting plates is typically comparable to ridge‐push, but ranges to 5× larger; slab‐pull moves the plate toward the trench (6 cases) or is neutral (1 case). Under the 6 largest plates with no attached slabs, basal tractions are 0.1∼1.2 MPa. Implications for Earth mechanics include: (a) Plate‐boundary faults are weakened by low‐friction minerals in oceanic transform faults, temporary coseismic pore pressure elevation in many continental transforms, and permanent high pore pressure in subduction megathrusts; (b) Such weak faults are rare in plate interiors, which display Byerlee's Law friction and dislocation creep strengths matching laboratory results; (c) Generally “forward” net slab pull and basal shear tractions help gravitational potential energy to drive the plates. Implications for future modeling include: (d) Fault elements are required; (e) Laboratory flow‐laws should replace Newtonian viscosity; and (f) Mohr‐Anderson friction should replace isotropic plasticity.

Abstract Recent three-dimensional flare models suggest that flare ribbon substructure is linked to the fragmentation of the reconnecting current sheet in the corona. Flare ribbon substructure can therefore potentially serve as a unique diagnostic tool for physical processes in the flare current sheet. In this paper, we describe a new method to quantify the evolution of ribbon substructure that first extracts the ribbon’s bright leading edge and then quantifies its morphology using the box-counting dimension and correlation dimension mapping (CDM). We first test our method using synthetic observations. We then apply it to an M6.5-class solar flare on 2015 June 22 observed by the Interface Region Imaging Spectrograph (IRIS) 1330 Å slit-jaw imager. We find that when the flare ribbon boundary has more multiple-spatial-scale features (a higher box-counting dimension), hard X-ray emission and magnetic reconnection rates are the strongest. We also find that the flare ribbon complexity characterized by CDM has a moderate correlation with the IRIS Si IV 1402.77 Å nonthermal velocity (in the negative polarity ribbon) and reconnection flux rates (in ribbons of both magnetic polarities). We conclude that the buildup of the spatial complexity of the ribbons at multiple spatial scales can serve as an observational proxy for current-sheet fragmentation in the corona.

Abstract Point sources are often major contributors of greenhouse gas and air pollutant emissions in urban areas. Dense air monitoring networks provide a unique avenue for studying point source emissions over long time periods. Here, we use the Berkeley Environmental Air‐quality and CO 2 Network (BEACO 2 N) to study CO 2 and air pollutant emissions from an oil refinery in the city of Richmond, CA. We identify 266 plumes crossing one or more sites in the BEACO 2 N network during 2022–2023 as having a source at the refinery and quantify CO 2 emissions using the Gaussian plume model. The refinery is modeled as two point sources, and total CO 2 emissions are found to be 61.3 ± 6.3 kg s −1 , in close agreement with the EPA Facility Level Information on GreenHouse gases Tool inventory and Carbon Mapper measurements. Additionally, plume composition was found to vary, with CO/CO 2 enhancement ratios ranging from 0 to 5 ppb/ppm. Taking the average CO/CO 2 ratio, CO emissions are estimated to be roughly 3,000 mt, a sizable amount compared to the city's estimated non‐refinery CO emissions of 6,800 mt. In addition, we show that dense monitoring networks provide a unique resource for point source emissions quantification with broad application to plumes of varying size and composition, and recommendations are laid out for future applications.

The emergence of biological complexity from abiotic chemistry remains thermodynamically unexplained. Existing frameworks, such as Prigogine's minimum entropy production theorem, the maximum power principle (Lotka and Odum), and exergy (Rant) each capture one aspect of a dissipative structure, but none has quantified all its thermodynamic properties as a coherent set derived from a single physical model. This paper introduces the gravitational dissipative structure (GDS) and provides that complete quantitative framework. Grounded in Clausius's interior/exterior work distinction and his force-balance reversibility criterion, the GDS model derives six thermodynamic properties, including complexity yield, specific heat quality, and heat transformation effectivity, and proves two theorems: first, that dissipative structures are more effective at transforming heat into stored energy at greater local heat sink temperatures; second, that the ratio of real efficiency to Carnot efficiency is constant regardless of boundary temperatures. Applied to Earth's tropospheric water and air cycles, the model yields auto-powering capacities of 82 W/m² and 345 W/m², with 98.8% of initial heat quality retained. Their combined heat quality outputs estimate the actual measure of jet stream velocity to within the same order of magnitude, cross-validating the GDS model and the concept of heat quality networking. When GDSs network at planetary scale, the result is massive mixing, a geological-timescale concentration of dissolved salts, acids, bases, and minerals that provides the multiplicity of microstates and ergodicity of mixing required for spontaneous prebiotic chemistry. This is Part I of a four-part series; Parts II through IV build on these preconditions to demonstrate the inevitability of life. Earth is a naturally-organizing machine, driven by heat and conservative forces to generate life.