Numerical weather prediction is pushing the envelope of grid resolution at local and global scales alike. Aiming to model topography with higher precision, a handful of articles introduced unstructured vertical grids and tested them for dry atmospheres. The next step towards effective high-resolution unstructured grids for atmospheric modeling requires that also microphysics is independent of any vertical columns, in contrast to what is ubiquitous across operational and research models. In this paper, we present a non-column based continuous and discontinuous spectral element implementation of Kessler’s microphysics with warm rain as a first step towards fully unstructured atmospheric models. We test the proposed algorithm against standard three-dimensional benchmarks for precipitating clouds and show that the results are comparable with those presented in the literature across all of the tested effective resolutions. While presented for both continuous and discontinuous spectral elements in this paper, the method that we propose can very easily be adapted to any numerical method utilized in other research and legacy codes.

The article proposes a straightforward Kalman filter-based method for computationally efficient ionospheric electron density multi-instrument imaging. The approach uses direct ionospheric measurements, such as ionosondes, and general physical assumptions to estimate the uncertainty associated with the previous reconstructed time step. Therefore the method does not require any electron density model of the ionosphere as a background. The uncertainty is represented by an inverse covariance matrix constructed with Gaussian Markov random fields, allowing the problem to be solved numerically with relatively high resolution. The experiments utilise measurements from dense ground-based GNSS and low Earth orbit beacon satellite receiver networks as well as ionosondes. A synthetic simulation study and real data validation with a specific EISCAT incoherent scatter radar measurement campaign is carried out over Northern European sector. The method can be controlled using parameters with probabilistic and physically realistic interpretations that can be applied to both simulated and real-world data. The results show that the approach is feasible for near real-time regional ionospheric imaging. Especially, the method can be seen as an expansion to local profile measurements field of view, but with sufficient measurement coverage, it also provides information further away from the specific instrument.

In this study we investigate whether a better representation of precipitation in the Amazon basin arises through an explicit representation of convection and whether it is related to the representation of organized systems. In addition to satellite data, we use ensemble simulations of the ICON-NWP model at storm-resolving (2.5-5.0 km) scales with explicit convection (E-CON) and coarse resolutions, with parameterized convection (P-CON). The main improvements in the representation of Amazon precipitation by E-CON are in the distribution of precipitation intensity and the spatial distribution in the diurnal cycle. By isolating precipitation from organized convective systems (OCS), it is shown that many of the well simulated precipitation features in the Amazon arise from the distribution of these systems. The simulated and observed OCS are classified into 6 clusters which distinguish nocturnal and diurnal OCS. While the E-CON ensembles capture the OCS, especially their diurnal cycle, their frequency is reduced compared to observations. Diurnal clusters are influenced by surface processes such as cold pools, which aid to the propagation of OCS. Nocturnal clusters are rather associated with strong low-level easterlies, possibly related to the Amazonian low-level jet. These particular environmental conditions provide insights on the processes that are important for OCS in the Amazon and should be further improved.

Long-term fault growth involves the dynamic evolution of fault zone architecture, structural maturity, and physical properties. Accurate characterization of these features is essential for improved understanding of fault mechanics, rupture dynamics and earthquake hazard. Fault structural maturity has traditionally been quantified via analysis of geological features. Nonetheless, the manifestations of an incipient fault are still poorly known, partly due to a lack of fault outcrops and limited diagnostic characteristics of this type of fault. In this study, we integrate coseismic and postseismic geodetic (InSAR/GPS) observations, relocated aftershocks, optical satellite imagery, and field measurements to characterize the fault kinematics of the May 21 2001 Mw7.4 Maduo earthquake, which occurred on an immature fault. Using relocated aftershocks, we determine the fault damage zone thickness and damage density decay at a comparable resolution with field geological investigations. We analyze surface inelastic strain along the rupture using both InSAR and optical images. We construct a buried slip model and refine the coseismic slip distribution to determine a shallow slip deficit, which we attribute to off-fault deformation. We also examine the afterslip distribution and moment release following the earthquake to probe its relationship with coseismic rupture. All pieces of evidence point to the dominant role of immaturity of the fault hosting the Maduo earthquake. Our study demonstrates that the combined analysis of seismological data, geodetic observations and field measurements helps to comprehensively characterize fault structural maturity and to better understand the role of single earthquakes in the long-term fault zone evolution.

The strength and sliding behavior of faults in the crust is largely controlled by friction and effective stress, which is itself modulated by fluid pressure. Most earthquake models assume a fixed pore fluid pressure despite widespread evidence that is varies strongly in time due to changes in permeability. Here we explore how dynamic changes in pore pressure influence the properties of earthquakes in the upper crust. To study this problem we develop a two dimensional model that incorporates slow tectonic loading and fluid pressure generation during the interseismic period with frictional sliding on a thrust fault whose permeability evolves with slip. We find that the presence of relatively modest fluid overpressures tends to reduce coseismic slip, stress drop, maximum sliding velocity, rupture velocity and the earthquake recurrence time compared to models without fluids. Our model produces a wide range of sliding velocities from rapid to slow earthquakes, which occur due to the presence of high pore pressures prior to rupture. The models also show evidence for aftershocks that are driven by fluid transfer along the fault plane after the mainshock. Overall, this study shows that fluids can exert an important influence on earthquakes in the crust, which is mostly due to modulation of the effective stress and variations in permeability, and to a lesser extent to poro-elastic coupling.

Forest fires significantly impact permafrost degradation in the subarctic regions. However, inter-annual and seasonal variations in surface deformation due to permafrost thawing in burned areas were poorly understood. Measuring the ground surface displacement in fire scars helps us understand the freeze–thaw dynamics of near-surface ground and predict the future state, particularly in ice-rich permafrost regions. This study used the L- and C-band interferometric synthetic aperture radar (InSAR) technique to reveal inter-annual subsidence and seasonal thaw settlement/frost heave in a fire scar near Mayya, Sakha Republic in Eastern Siberia burned in 2013. We found that the cumulative subsidence was up to 7 cm between 2014 and 2020, most of which had occurred by 2016. The magnitude of seasonal thaw settlement and frost heave varied each year from 2017 to 2020 after the fire, but the inter-annual change in frost heave corresponded to the temporal variation in precipitation during the thawing season from 2017 to 2020. This suggests that the precipitation amount during the thawing season is related to the magnitude of segregation–ice formation in the sediments, which determines the frost heave amount. The observed seasonal displacements could not be quantitatively explained by models inferred from the Stefan’s equation and volume changes associated with ice–water phase change. This implies that other models associated with segregated ice (ice lens) formation/thaw are required to explain the observed seasonal displacement.

Numerical simulations of the tropical mesoscales often exhibit a self-reinforcing feedback between cumulus convection and shallow circulations, which leads to the self-aggregation of large cloud structures. We investigate whether this basic feedback can be adequately captured by large-eddy simulations (LESs). To do so, we simulate the non-precipitating, cumulus-topped boundary layer of the canonical ‘BOMEX’; case over a range of numerical settings in two models. Since the energetic convective scales underpinning the self-aggregation are only slightly larger than typical LES grid spacings, aggregation timescales do not converge even at rather high resolutions (less than 100m). Therefore, high resolutions or improved unresolved scales models may be required to faithfully represent certain forms of trade-wind mesoscale cloud patterns and self-aggregating deep convection in large-eddy and cloud-resolving models, and to understand their significance relative to other processes that organise the tropical mesoscales.

A three-color, extremely high signal to noise, precisely pointed, sub-arcsecond photometer would enable us to distinguish Earth-like exoplanets from other rocky, gassy, or icy worlds - if we had the right three wavelengths, and the ability to block out the primary star’s glare. Color-color discrimination of Earth-like planets has been posited for quite some time. Broadband filters are not seen to be precise diagnostics of planets with life, but rather broad but critical similarity or difference to the one habitable planet we know. Visible wavelengths (Vis) are advantageous due to relatively greater abundance of photons of that wavelength range from planets around Sun-like stars. Near-ultraviolet (UV) wavelengths may be advantageous due to ozone and scattering properties in Earth’s atmosphere that make Earth truly stand out from other known and modeled planets. Near infrared wavelengths (IR) help discriminate potential biological color contributions. We conducted an optimization exercise to arrive at three broadband filters that reliably separate modeled Earth-like, nominally habitable planets from other possible exoplanets. Criteria we use included: - Atmosphere/clouds of habitable worlds - Sea/Land proportions (ocean, granite, basalt, other surface material) - Vegetation (chlorophyll spectra and fictional other photosynthetic materials depending on wavelengths of parent stars etc.) - Other factors that can be spectrally modeled (planet-covering cities, world oceans, etc.) The optimized bands resemble previous work for exoplanets and the solar system, but underscore the advantage of UV wavelengths and indicate their potential utility for exoplanet identification and/or discrimination in concert with other exoplanet observations. An exoplanet survey that could quickly identify such planets could then be followed up by more detailed, longer term study by more intensive campaigns with more capable, but more resource or time constrained.

The ultraviolet imager (UVI) of the Polar spacecraft and an all-sky camera at Longyearbyen contemporaneously detected an auroral vortex structure (so-called “auroral spiral”) on 10 January 1997. From space, the auroral spiral was observed as a “small spot” (one of an azimuthally-aligned chain of similar spots) in the poleward region of the main auroral oval from 18 h to 24 h magnetic local time. These auroral spots were formed while the substorm-associated auroral bulge was subsiding and several poleward-elongated auroral streak-like structures appeared during the late substorm recovery phase. During the spiral interval, the geomagnetically north-south and east-west components of the geomagnetic field, which were observed at several ground magnetic stations around Svalbard island, showed significant negative and positive bays caused by the field-aligned currents related with the aurora spiral appearance. The negative bays were reflected in the variations of local geomagnetic activity index (SML) which was provided from the SuperMAG magnetometer network at high latitudes. To pursue the spiral source region in the magnetotail, we trace each UVI image along field lines to the magnetic equatorial plane of the nightside magnetosphere using an empirical magnetic field model. Interestingly, the magnetotail region corresponding to the auroral spiral covered a broad region from Xgsm ~ -40 to -70 RE at Ygsm ~ 8 to 12 RE. The appearance of this auroral spiral suggests that extensive areas of the magnetotail (but local regions in the ionosphere) remain active even when the substorm almost ceases, and geomagnetic conditions are almost stable.

Since the famously inconclusive Viking missions, we have observed an increased desire to discover life outside the Earth. However, if we are to plan effective life-detection missions, then we must meet the challenge of classifying potential “agnostic” biosignatures (indicators of life or the absence of life). Agnostic refers to attempting to not use biosignatures that would bias towards Earth centric life standards, which would be “putting the answer in the question.” Machine learning techniques, specifically statistical classification already showed promising results in other fields. Applied to astrobiology, it may provide clarity on how different and independent measurements of the same biosignature affects your confidence in whether it is indicative of life. In this work, these algorithms were implemented to classify Raman spectra of potential biosignatures. Data was collected from public databases and individual research papers, processed, and then evaluated with several different algorithms. After thousands of simulations to allow the algorithms to test their classifications, we observed an 81% probability of correct classification when all the algorithms’ individual predictions were combined. These results demonstrate Raman spectroscopy’s potential for life-detection missions, and ability to improve upon a qualitative criterion for identifying indicative of life biosignatures.

Conductivity of the ionosphere allows the complex system of magnetospheric currents to flow through. Conductivity is governed by several factors including electron density and temperature, whose influence is highly dynamic during geomagnetic storm events. Thus, it is a crucial parameter that must be determined for space weather modeling to specify the coupling between the magnetosphere, ionosphere and thermosphere systems. Major sources of ionospheric conductivity are solar EUV and particle precipitation which includes Diffuse (Diff.), Monoenergetic (ME) and Broadband (BB) precipitations. Conductance Σ is the height integrated version of conductivity. Empirically, total ionospheric conductance (Hall and Pedersen) is known to be the root sum square of individual conductance terms [Wallis and Budzinski, 1981], considering that conductivity resulting from different processes are not linearly additive and corresponding ionization rates shall be added at each altitude and then integrated over the desired altitude range. With the inclusion of the less energetic broadband precipitation that was found to cause ionization in the bottom-side F region, the expression for the total ionospheric conductance was modified by the linear addition of the contribution of the broadband precipitation to the total Hall and Pedersen conductance[Zhang et al., 2015].In this study, using a 3-dimensional global physics based model GITM (Global Ionosphere Thermosphere Model), the validity of this combination of vector and linear addition of individual source terms to the total ionospheric conductance is examined and the more accurate expression for the summation of sources contributing to the total conductance is quantified. GITM is employed to calculate the Hall and Pedersen conductance using the average energy, potential and energy flux for each of the sources of conductance. Several scenarios are simulated where the different sources of precipitation are paired with solar EUV radiation, and the total conductance is obtained. Linear and vector summation of conductance resulting from combinations of sources and individual sources indicate that the contribution of broadband precipitation to the total conductance also follows vector addition. To quantify the result that the total conductance is the vector sum of individual sources, error histograms are plotted and a set of metrics including RMSE, mean error, standard deviation, correlation coefficient and fractional error are enumerated for both linear and vector summation of individual sources to produce the total conductance.

Purell kills 99.99% of the most common germs which cause illnesses. This means that 0.01% of bacteria still remains on the skin surfaces of the organism. Optimal bactericidal efficacy is at 60-90% concentration as even pure alcohol is less bactericidal. Purell consists of ethanol which proves to be most effective in virucidal activity. Adding aqueous solution to ethanol solutions can increase its efficacy against viruses that are more resistant to ethanol alone. However, it is well known that hand sanitizers are ineffective against non-developed viruses. Alcohol-based hand sanitizers are very effective for quickly destroying many pathogens through aqueous alcohol solutions. This study tests the effectiveness of alcohol-based sanitizer concentrations on specific types of epidermal bacteria. This experiments alcohol-based sanitizer concentrations on two types of epidermal floras, Staphylococcus epidermidis and Escherichia coli B. To test this hypothesis, a two-part procedure was conducted using the Kirby-Bauer method. Low, high, and optimal concentration solutions are formulated as the experimental group while the control group is a pure aqueous solution. Using sterile technique, cultures of Staphylococcus epidermidis and Escherichia coli B were dispensed onto Petri dishes and tested with each different concentration type. The results of Escherichia coli B disproved the hypothesis as high concentration levels were most effective in regulating its presence while Staphylococcus epidermis modulated best under optimal concentrations. This considers the effectiveness of sanitizer on bacteria that remains on the epidermis even after Purell is applied and can display how concentration modifications affect the growth of bacteria.

On January 15, 2022, we observed various unusual atmospheric wave events over the South American sector: Atmospheric pressure waves (Lamb mode) around 12:30 to 17:30 UT, Tsunamis along the Chile coast at around 17:00 to 19:00 UT, and related ionospheric disturbances between 11:30 and 20:00 UT. We understand that these events were generated by the Tonga volcanic eruption that occurred at (20.55°S, 175.39°W) in South Pacific Ocean at 04:15 UT. Several Traveling Ionospheric Disturbances (TIDs) were observed before and after the Lamb wave passed over the continent and the arrival of the tsunami on the Chile coast. This is the first time to report the signature of ionospheric disturbances over the South American continent generated by both the Lamb wave and the tsunami that were produced by the huge volcanic eruption.

New relative paleointensity results from mafic lava flows erupted in quick succession during four Neogene geomagnetic reversals show that volcanic transition zones can provide a favorable setting for the pseudo-Thellier technique. The most compelling data are from a normal-to-reverse (N-R) transition zone in the 4 my old basaltic lava flows of the Olokele Formation on Kauai (Hawaii). Following stepwise alternating field (AF) demagnetization of each sample’s natural remanent magnetization, an anhysteretic remanent magnetization (ARM) was imparted in a 50 uT bias field and then AF demagnetized. Very similar behavior of the 35 mT to 90 mT coercivity fractions suggest that the NRM (interpreted to be a primary thermoremanent magnetization (TRM)) and ARM reside in the same subpopulation of magnetic grains. With the ARM intensity serving as an analog for TRM susceptibility, the 35 mT-90 mT TRM/ARM ratios provide a relative measure of the ancient field intensity. Good correlation of flow-mean TRM/ARM ratios with a small set of double-heating paleointensities from companion samples allows an approximate scaling of the TRM/ARM ratios to absolute intensity. As the geomagnetic polarity switched, the field strength apparently dropped by 91% compared to the maximum recorded by the flows. This decrease is comparable to that observed in other paleomagnetic studies and numerical simulations. During an interval of NE-down directional stasis recorded by a succession of 10 flows in the lower half of the section, the geomagnetic intensity rose to over 20 uT and then decreased to near 5 uT. This distinctive behavior could mark the waxing and waning of a stationary, inward-directed flux patch on the core mantle boundary centered NE of Kauai. Within-flow variability of relative paleointensity was higher in two other Pliocene transition zones on Kauai (both R-N), and in the R-N transition recorded by 15.2 my old lavas in the Sheep Creek Range (Nevada). Nevertheless, all three records document a reduction in the ancient geomagnetic field intensity similar in magnitude to that seen in the Olokele flows. The relative uniformity of magnetic mineralogy may help explain why the pseudo-Thellier technique was able to capture the large transitional intensity changes recorded by these rapidly-erupted flow sequences.

Tomographic analysis of Pn arrivals times—the guided P-wave propagating within the lithospheric mantle—is ideal for studying the structure of the uppermost mantle. While plate-scale seismic images of Pn wave speeds are common beneath the continents, similar scale studies have not been possible within ocean basins due to the sparsity of seismic stations. The Cascadia Initiative (CI) dataset provides the first opportunity to image spatial variations in lithospheric structure across an entire oceanic plate. We measure 2,862 Pn arrivals from local earthquakes recorded by the CI array. Our dataset provides complete coverage of both the Juan de Fuca (JdF) and deforming Gorda plates. We invert the measured arrival times for 3D variations in anisotropic P-wave velocity and hypocentral parameters. Despite surficial evidence of extensive active faulting, the velocity structure of the Gorda uppermost mantle is remarkably consistent with predictions from a conductive cooling model (attached figure). Limited deformation at mantle depths is supported by seismic anisotropy measurements that show the fast-direction of P-wave propagation rotates in concert with the magnetic anomaly lineations. This rotation may be explained by local plate kinematics without internal deformation and hydration of the shallow mantle. In contrast to Gorda, the seismic velocity structure of the JdF plate does not exhibit a clear age dependence. Three pronounced mantle low-velocity zones are found along the southern edge of the JdF plate near the termini of large pseudofaults that contributed to the formation of the Blanco Transform fault. We attribute these velocity reductions to mantle alteration by seawater. We note that within the interior of the JdF plate pseudofaults do not appear as uniformly slow features in our seismic images. Beneath the central and northern JdF plate, P-wave speeds are ~7.7 km/s out to ~4-5 Myr before abruptly increasing to ~7.9 km/s. Curiously, this transition occurs near the onset of mantle downwelling inferred from teleseismic body wave tomography and attenuation suggesting that mantle flow dynamics may influence the structure of young oceanic lithosphere. Lastly, we note that our results do not suggest a relationship between the structure of the uppermost slab mantle and segmentation of the Cascadia megathrust.

As Earth System Science (ESS) becomes more data-intensive, collaborative, and interdisciplinary, it is important to understand how best to support and advance data reuse. We conducted an online survey of active ESS researchers from 126 U.S. universities and research centers, representing a wide variety of scientific fields. Of the 207 respondents, 51.7% had more than 20 years of research experience. Results indicated that the current primary purposes for reusing data are to conduct new analysis (87%), followed by comparing results (70.4%), with only 18.5% reusing data to reproduce published studies. As expected, data hosted by federally funded data centers were reused most frequently, with open government data and data provided directly from other researchers also widely used. Reuse of data from other types of repositories lags far behind, due in part to a range of service limitations. At the same time, data sharing by respondents is strong—96.6% actively release their data, primarily as supplements to published papers, with moderate use of open access repositories. Of the 45.9% who had attempted to reproduce research, 73.7% failed at least once, often due to the limited detail provided in published papers. Still, 92.3% believe it is the researcher’s responsibility to ensure their work is reproducible. The majority favored traditional modes of documenting research—word processors, text editors, and code commenting over electronic notebooks or workflow systems. Interestingly, 59.9% continue to use hand-written notebooks. Challenges to data reuse and reproducibility specific to ESS included the complex nature of earth systems, increasingly complicated models, lack of data management resources, and limited emphasis on reproducibility in the field. Open-ended responses raised questions about whether “exact replication” is necessary or possible for ESS. Most researchers agreed that data and code should be considered important research products and that outlets are needed for publishing negative results. Taken together, the results suggest a strong data sharing culture in ESS with high levels of reuse and commitment to open science. The research community would benefit greatly from better documentation and sharing of methods and research processes, as well as targeted improvements in data services and tools.

During the mid-Holocene (MH, 6,000 years BP), precessional forcing drove enhanced monsoon rainfall, expanded vegetation cover, and reduced dust emissions throughout the African Sahara. The orbital forcing and feedback of vegetation albedo have been widely studied with climate models, but are found to be insufficient to explain the magnitude and location of rainfall anomalies suggested from proxy reconstructions. The feedback of reduced Saharan dust loading has been less-studied because Paleoclimate Modelling Intercomparison Project (PMIP) Phase 2/3 models did not incorporate the decreased MH Saharan dust emissions. Several recent modeling studies investigated the MH Saharan hydroclimate response to reduced dust loading; however, their models only resolved the direct effect from dust aerosols (i.e. direct radiative forcing), which leaves the contribution from indirect dust aerosol effects (i.e. dust aerosol-cloud interactions) largely unknown. Here we investigate the hydroclimate response due to Saharan dust using CESM CAM5-chem, which includes both the direct and indirect dust aerosol effects. In the simulations, reduced Saharan dust directly increases monsoon season (JJAS) net shortwave radiative flux at the surface, which drives continental warming. Convective clouds and convective precipitation are subsequently enhanced and, due to the overwhelming convective nature of this monsoonal region, total Saharan (20–31°N, 20°W–30°E) precipitation increases by 11.9%. However, indirect dust aerosol effects counteract the increase from convection precipitation. A reduction in Saharan dust decreases cloud nuclei number concentration and increases cloud droplet size, which in turn reduces stratus cloud cover and large-scale stable rainfall. Overall, the decrease in large-scale stable rainfall due to indirect dust effects reduces total precipitation by 12.5%. The total rainfall increase of 0.27 mm/day from reduced dust is significant but smaller than the response to changes in vegetation cover (1.19 mm/day). While these results indicate that less Saharan dust during the MH likely enhanced Saharan rainfall, they also suggest that a reduction in the indirect effects of dust likely dampened the overall response of rainfall to the MH dust forcing.

In 2007, the National Academies designated “understanding the structure & composition of the lunar interior” (to provide fundamental information on the evolution of a differentiated planetary body) as the second highest lunar science priority that needed to be addressed. Here we present the current status of the planned response of the Lunar Geophysical Network (LGN) team to the upcoming New Frontiers-5 AO. The Moon represents an end-member in the differentiation of rocky planetary bodies. Its small size (and heat budget) means that the early stages of differentiation have been frozen in time. But despite the success of the Apollo Lunar Surface Experiment Package (ALSEP), significant unresolved questions remain regarding the nature of the lunar interior and tectonic activity. General models of the processes that formed the present-day lunar interior are currently being challenged. While reinterpretation of the Apollo seismic data has led to the identification of a lunar core, it has also produced a thinning of the nearside lunar crust from 60-65 km in 1974 to 30-38 km today. With regard to the deep mantle, Apollo seismic data have been used to infer the presence of garnet below ~500 km, but the same data have also been used to identify Mg-rich olivine. A long-lived global lunar geophysical network (seismometer, heat flow probe, magnetometer, laser retro-reflector) is essential to defining the nature of the lunar interior and exploring the early stages of terrestrial planet evolution, add tremendous value to the GRAIL and SELENE gravity data, and allow other nodes to be added over time (ie, deliver the International Lunar Network). Identification of lateral and vertical heterogeneities, if present within the Moon, will yield important information about the early presence of a global lunar magma ocean (LMO) as well as exploring LMO cumulate overturn. LGN would also provide new constraints on seismicity, including shallow moonquakes (the largest type identified by ALSEP with magnitudes between 5-6) that have been linked to young thrust fault scarps, suggesting current tectonic activity. Advancing our understanding of the Moon’s interior is critical for addressing these and many other important lunar and Solar System science and exploration questions, including protection of astronauts from the strong shallow moonquakes.