With shore-fast sea ice disappearing along the coast of the Chukchi Sea causing winds with deep snow drifts, variable snowpack in Bristol Bay in Alaska, and winters without snow in West Central Montana, youth from these areas have personal stories of environmental changes witnessed firsthand. In a virtual “Dirty Snow” citizen science STEM engagement program that met weekly for 5-weeks, middle and high school youth across different time zones and cultures shared such snow stories, implemented a protocol to measure light absorbing particles (LAPs) in snow, and conducted their own Global Learning and Observations to Benefit the Environment (GLOBE) snowpack and pH investigations. Teachers, parents and researchers teamed up to support students as they asked their own questions about how LAPs affect their local communities and measured, collected, filtered, and analyzed snow samples. Students learned that LAPs in snow affect the Earth’s climate system by reducing snow reflectivity, affecting albedo. On a local scale, LAPs capture heat energy leading to snow loss. Students wondered if LAPs also affect water quality. Middle school students from Shishmaref, Alaska (located on an island in the Chukchi Sea) selected snow sampling locations in areas important to their community’s resilience to climate change, such as the sole water supply lagoon. The Shishmaref students shared their results with their community, showcased their project in both the GLOBE International Virtual Science Symposium and a tribal climate resilience webinar, and have been featured in the July 2021 Association of Women in Science Magazine issue on sustainability and innovation. In this session, we will share the lessons learned from multiple perspectives - including surveyed youth participants - on conducting a remote synchronous and asynchronous STEM and climate resilience engagement on a short timescale.

In a reference frame rotating with Mercury’s mantle and crust, the inner core and fluid core precess in a retrograde sense with a period of 58.646 days. The precession of a triaxial inner core with a different density than the fluid core induces a periodic gravity variation of degree 2, order 1. Elastic deformations from the pressure that the precessing fluid core exerts on the core mantle boundary also contribute to this gravity signal. We show that the periodic change in Stokes coefficients ΔC21 and ΔS21 for this signal of internal origin is of the order of 10^{-10}, similar in magnitude to the signal from solar tides. The relative contribution from the inner core increases with inner core radius and with the amplitude of its tilt angle with respect to the mantle. The latter depends on the strength of electromagnetic coupling at the inner core boundary which in turn depends on the radial magnetic field B_r; a larger B_r generates a larger tilt. The inner core signal features a contrast between ΔC21 and ΔS21 due to its triaxial shape, discernible for an inner core radius >500 km if B_r>0.1 mT, or for an inner core radius >1100 km if B_r<0.01 mT. A detection of this contrast would confirm the presence of an inner core and place constraints on its size and the strength of the internal magnetic field. These would provide key constraints for the thermal evolution of Mercury and for its dynamo mechanism.

A document by Yu-Hai Wang. Click on the document to view its contents.

The stated mission of the International Arctic Research Center (IARC) at the University of Alaska Fairbanks (UAF) is ”to foster Arctic research to help the nation and the world understand, prepare for, and adapt to the pan-Arctic impacts of climate change.” IARC’s work and collaborations are everywhere in the Arctic and beyond. One of IARC’s core values is actively cultivating an environment of diversity and inclusion where all individuals and groups feel welcomed and are heard. Through the work of the IARC Diversity and Inclusion Working Group, we affirm that our different experiences, expertise, and ways of knowing are our strength, fostering diverse thoughts and ideas. Collaborative science and administrative support by people from diverse backgrounds and knowledge systems helps IARC build a professional culture of inclusion, listening, caring and respect. We face challenges in DEI work and are actively addressing them. For example, in addressing the challenge of time constraints by the all-volunteer membership, a DEI coordinator position to spearhead our efforts is being created and funding sought. We highlight efforts from the IARC Diversity and Inclusivity Working Group to cultivate a culture of inclusion, equity and access: 1) collaboratively developing an institutional diversity and inclusivity statement and land acknowledgement statement, 2) creating safe spaces for conversation and action through open biweekly working group meetings and discussions, 3) elevating awareness through relevant workshops, trainings and discussions, 4) collectively incorporating diversity and inclusion values into the IARC strategic plan, 5) making presentations and documents accessible, and 6) actively collaborating on inclusion efforts within UAF, Alaska and beyond. We welcome new members with their ideas and perspectives to the working group. At IARC, we recognize that inclusion is an ongoing process that has to be woven into all that we do in research, education and outreach.

Climate change may alter access to safe drinking water, with important implications for health. We assessed the relationship between temperature and rainfall and utilization of basic drinking water (BDW) in The Gambia, Mozambique, Pakistan, and Kenya. The outcomes of interest were 1) whether the reported drinking water source used in the past two weeks met the World Health Organization definition of BDW and 2) use of a BDW source that was always available. Temperature and precipitation data were compiled from weather stations and satellite data and summarized to account for long- and short-term weather patterns and lags. We utilized random forests and logistic regression to identify key weather variables that predicted outcomes by site and the association between important weather variables and BDW use. Higher temperatures were associated with decreased BDW use at three of four sites and decreased use of BDW that is always available at all four sites. Rainfall, both in the long- and short-term, was associated with increased BDW use in three sites. We found evidence for interactions between household wealth and weather variables at two sites, suggesting lower wealth populations may be more sensitive to weather-driven changes in water access. Changes in temperature and precipitation can alter safe water use in low-resource settings – investigating drivers for these relationships can inform efforts to build climate resilience.

This study utilizes a novel technique to separate and classify different ionospheric troughs from CHAMP satellite data in the winter midnight ionosphere of the southern hemisphere at high solar activity (2000–2002). The main ionospheric trough (MIT) was separated from the high latitude trough (HLT). The separation was performed through an analysis of troughs in the frame of the model of the diffuse auroral particle precipitation. Two types of HLT were distinguished. In the mid-latitude ionosphere, the MIT was separated from the ring ionospheric trough (RIT), which is formed by the decay processes of the magnetospheric ring current. The separation was performed on the basis of an analysis of the prehistory of all geomagnetic disturbances for the period under study. In addition to the RIT, an equatorward decrease in the electron density, which is superimposed on the MIT and masks it, forms quite often at American and Atlantic longitudes.

Coseismic rotations of principal stress axes can provide insights into the strength of the crust, but it is unclear how common this phenomenon is. We use a nearest-neighbor clustering algorithm to identify earthquake sequences in the global ISC-GEM catalog and the regional Southern California catalog. Using an inner-product-based pairwise measure of moment tensor similarity, we demonstrate that, in both catalogs, aftershocks are less similar to their respective mainshocks than foreshocks are. We interpret this effect, which we call moment tensor scattering, as evidence for widespread coseismic stress rotations. Moment tensor scattering is observable for a broad range of mainshock magnitudes in both catalogs. We further demonstrate that mainshock-aftershock similarity recovers logarithmically to pre-mainshock levels on decadal timescales. We conclude that moment tensor scattering is a generally observable feature of seismic sequences which may be useful in future work to discriminate between models of crustal strength.

Previously the radiation patterns of combined parallel and perpendicular motions from the accelerated relativistic particle at low and high frequencies of the bremsstrahlung process with an external lightning electric field were explained. The primary outcome was that radiation patterns have four relative maxima with two forward peaking and two backward peaking lobes. The asymmetry of the radiation pattern, i.e., the different intensities of forwarding and backward peaking lobes, is caused by the Doppler effect. A novel outcome is that bremsstrahlung has an asymmetry of the four maxima around the velocity vector caused by the curvature of the particle's trajectory as it emits radiation. This extended work reports another novel asymmetry in the overall radiation pattern. Previously stated bremsstrahlung asymmetry, R was an asymmetry in the radiation lobe pairs about particles velocity vector. Bremsstrahlung asymmetry used to occur at the same level in both forward radiation lobe pairs and backward radiation lobe pairs. However, in high-density mediums where the emitted wave can lag behind the speed of the particle, symmetry of the magnitude of bremsstrahlung asymmetry, R differs between forward peaking radiation lobe pairs relative to backward peaking radiation lobe pairs. This is another novel asymmetry and it causes bremsstrahlung asymmetry, R to be larger in the forward peaking compared to backward peaking radiation. The outcome is the shrink in radiation length that occurs in the backward peaking lobes. This extended mathematical modeling of the bremsstrahlung process into different high-density mediums helps to better understand the physical processes of a single particle's radiation pattern, which might assist the interpretation of observations with networks of radio receivers and arrays of gamma-ray detectors.

In this study, we use observations of THEMIS and Van Allen Probes to statistically study the modulations of chorus emissions by variations of background magnetic field and plasma density in the ultra low frequency range. The modulation events are identified automatically and divided into three types according to whether the chorus intensity is correlated to the variations of magnetic field only (Type B), plasma density only (Type N) or both (Type NB). For THEMIS observations, the occurrences of the types B and N are larger than type NB, while for Van Allen Probes observations most events are Type N. The chorus intensity is mostly correlated to the magnetic field strength negatively and plasma density positively. Modulation event occurrences peak at the dawn sector. The chorus intensity tends to increase when the magnitude of the magnetic field perturbation increases, but little dependence on the amplitude of plasma density perturbation is found.

This work proposes a new lateral extrusion dynamic model based on geological evidence, mathematical modeling and 3D discrete element simulation to explain the southeastward thrusting during the closure of the Songpan-Ganze basin. The Late Triassic NE-SW compression caused by the northward movement of the Qiangtang Block and the resulting differential shortening within the wedge-shaped Songpan-Ganze terrane produced southeastward topographic gradient. The thick sedimentary pile, decoupled from the subducting basement by the low-strength decollement, was driven by gravity and laterally extruded, leading to the southeastward Longmenshan thrusting. Therefore, the Longmenshan thrust belt is a lateral foreland thrust belt of the Songpan-Ganze terrane. The mathematical modeling provides detailed description of the differential shortening occurred within the Songpan-Ganze terrane. The 3D discrete element simulation, which is first time used for the geological study of the Longmenshan area, clearly reproduces the dynamical process of the Longmenshan southeastward thrusting and well predicts the Xiaojin Arcuate Zone. Both mathematical modeling and discrete element simulation verify the new lateral extrusion dynamics and reveal that two key factors facilitate the lateral extrusion and foreland thrusting, which are the wedge-shaped geometry that produces differential shortening and lateral topographic gradient, and the low-strength decollement that decouples the extruded sedimentary pile from the basement. The lateral foreland thrust belt, which has specializations in its tectonic location and dynamic behavior, is a new kind of foreland thrust belt after pro-foreland thrust belt and retro-foreland thrust belt, and provides a new insight into the tectonic evolution of collisional orogens.

Meteorology is a major driving force to poor urban air quality. This is due to its ability to influence the emissions, transport, formation, and deposition of air pollutants. In this study, the relationship between meteorological parameters including temperature, relative humidity, wind speed and direction and ambient air pollutants concentrations such as PM2.5 in the capital city of Ghana was carried out for a continuous period of 12 months from March 2020 to February 2021. Clear seasonality was observed for PM2.5, meteorological parameters and the air quality index. Maximum concentrations of PM2.5 were recorded in winter leading to poor air quality. Wind speed and relative humidity reversely correlated with the air pollutant while temperature showed a positive correlation with PM2.5. north-easterly winds led to highest concentrations during the winter season while south-westerly winds prevail over Accra in summer. The results from air quality index (AQI) indicated that severely poor air prevails during the winter period. These results justify the crucial role of meteorological parameters in air pollution formation with large variations in different seasons. These findings can be employed to enhance the understanding of processes that lead to air pollution and improve the accuracy of air quality forecast under different meteorological conditions.

Two of the most widely observed co-eruptive volcanic phenomena - ground deformation and volcanic outgassing - are fundamentally linked via the mechanism of magma degassing and the development of compressibility, which controls how the volume of magma changes in response to a change in pressure. Here we use thermodynamic models (constrained by petrological data) to reconstruct volatile exsolution and the consequent changes in magma properties. Co-eruptive SO2 degassing fluxes may be predicted from the mole fraction of exsolved SO2 that develops in magma whilst stored prior to eruption and during decompression. Co-eruptive surface deformation may be predicted given estimates of erupted volume and the ratio between chamber compressibility and magma compressibility. We conduct sensitivity tests to assess how varying magma volatile content, crustal properties, and chamber geometry may affect co-eruptive deformation and degassing. We find that magmatic H2O content has the most impact on both SO2 flux and volume change (normalised for erupted volumes). Our findings have general implications for typical arc and ocean island volcanic systems. The higher magmatic water content of arc basalts leads to a high pre-eruptive exsolved volatile content, making the magma more compressible than ocean island eruptions. Syn-eruptive gas fluxes are overall higher for arc eruptions, although SO2 fluxes are similar for both settings (SO2 flux for ocean island basalt eruptions is dominated by decompressional degassing). Our models are consistent with observation: deformation has been detected at 48% of ocean island eruptions (16/33) during the satellite era (2005-2020), but only 11% of arc basalt eruptions (7/61).

Convective mixing in the lower free troposphere (LFT) and its response to climate change are at the heart of low-cloud feedbacks in projections of future warming, but are challenging to diagnose from observations. The stable isotopic composition of water vapor in the LFT is a sensitive recorder of shallow convective moistening, and can potentially provide independent constraints on shallow convective processes. In-situ and remote sensing measurements from the southeast Pacific marine stratocumulus region and an isotope-enabled general circulation model (GCM) are used along with Gaussian process regression (GPR) to explore the utility of stable isotope measurements and simulations for improved estimates of shallow convective moistening tendencies in marine stratocumulus settings. We train the GPR algorithm on conventional and isotopic fields from a GCM (LMDZ5B) from the SE Pacific marine stratocumulus region and assess the algorithm on out-of-sample GCM output. The GPR trained on isotopic fields yields better estimates of shallow convective moistening tendencies than GPR trained only on conventional meteorological fields. Climate change is not well-captured if the GPR is trained only on the control climate, but performs much better if the training data include samples from both cool and warm climates, and is also reasonably well-captured if the GPR is only trained on the warm climate. The GPR algorithm is applied to isotopic and conventional measurements from the SE Pacific and yields realistic estimates of shallow convective moistening tendencies. Linking machine learning with isotopic simulations and measurements provides a unique and potentially useful framework for bridging GCMs and observations.

The Tonga volcano eruption of 15 January 2022 unleashed a variety of atmospheric perturbations, coinciding with the recovery phase of a geomagnetic storm. The ensuing thermospheric variations created rare display of extreme poleward-expanding conjugate plasma bubbles seen in the rate of total electron content index (ROTI) over 100-150°E. This is associated with fluctuations in FORMOSAT-7/COSMIC-2 (F7/C2) ion-density measurements and spread-F signatures in ionograms, reaching ~40°N geographic latitude. This was preceded by an unusually strong pre-reversal enhancement (PRE) in the global ionospheric specification (GIS) electron density profiles derived from F7/C2 observations. The GIS further revealed a decrease of equatorial ionization anomaly (EIA) crest density due to the storm impact. A sharp decrease of E-region conductivity by volcano-induced waves, combined with enhanced F-region wind over EIA with less ion-drag apparently intensified the PRE. The strong PRE and seed perturbations from the volcano-induced waves likely further triggered super plasma bubble activity.

The conduct of reproducible science improves when computations are portable and verifiable. A container provides an isolated environment for running computations and thus is useful for porting applications on new machines. Current container engines, such as Linux Containers (LXC) and Docker, however, have a high learning curve, are resource-intensive, and do not address the entire reproducibility spectrum consisting of portability, repeatability, and replicability. As part of EarthCube, we have developed Sciunit (https://sciunit.run) which encapsulates application dependencies i.e, system binaries, code, data, environment, along with application provenance. The resulting research object can be easily shared and reused amongst collaborators. Sciunit can be used with HydroShare’s JupyterHub CUAHSI notebook environment, and available to the entire community for use. In this poster, we will present three new features in Sciunit which have emerged based on community-provided use cases and discussion. Sciunit is available as a command-line utility. We will: (1) showcase the new Sciunit API. This will allow data facilities to integrate Sciunit as a reproducible environment on portals, (2) show how a Sciunit container can transition to a Docker container and vice versa, and finally, (3) demonstrate the ability to contrast two containers in terms of content and metadata. We will show these capabilities with the Hydrology use case of pySUMMA, a Python API for the Structure for Unifying Multiple Modeling Alternative (SUMMA) hydrologic model.

Gravity waves play an essential role in driving and maintaining global circulation. To understand their contribution in the atmosphere, the accurate reproduction of their distribution is important. Thus, a deep learning approach for the estimation of gravity wave momentum fluxes was proposed, and its performance at 100 hPa was tested using data from low resolution zonal and meridional winds, temperature, and specific humidity at 300, 700, and 850 hPa in the Hokkaido region (Japan). To this end, a deep convolutional neural network was trained on 29-year reanalysis datasets (JRA-55 and DSJRA-55), and the final 5-year data were reserved for evaluation. The results showed that compared to ground truth data, the fine-scale momentum flux distribution of the gravity waves could be estimated at a low computational cost. Particularly, in winter, when gravity waves are stronger, the median RMSE of the maximum momentum flux in the target area was 0.06–0.13 mPa.

The arrival of the Juno satellite at Jupiter has led to an increased interest in the dynamics of the Jovian magnetosphere. Jupiter’s auroral emissions often exhibit quasi-periodic oscillations with periods of tens of minutes. Magnetic observations indicate that ultra-low-frequency (ULF) waves with similar periods are often seen in data from Galileo and other satellites traversing the Jovian magnetosphere. Such waves can be associated with field line resonances, which are standing shear Alfvén waves on the field lines. Using model magnetic fields and plasma distributions, the frequencies of field line resonances and their harmonics on field lines connecting to the main auroral oval have been determined. Time domain simulations of Alfvén wave propagation have illustrated the evolution of such resonances. These studies indicate that harmonics of the field line resonances are common in the 10-40 minute band.

Non-volcanic tremor has been observed at the roots of many fault systems around the Pacific rim, including convergent and transform plate boundaries. The extent to which deep tremor signals are prevalent along plate boundaries elsewhere, including the Mediterranean basin, has not yet been documented in detail. A body of evidence suggests that tremor triggered during the surface waves of teleseismic events may commonly occur where ambient tremor during Episodic Tremor and Slip episodes occur, suggesting triggered tremor provides a useful tool to identify regions with ambient tremor. We perform a systematic search of triggered tremor associated with large teleseismic events between 2010 and 2020, at four major fault systems within the central-eastern Mediterranean basin namely the Hellenic and Calabrian subduction zones, and the North Anatolian and Kefalonia transform faults. In addition, we search for ambient tremor during a ~50-daylong slow slip event in the eastern Sea of Marmara along a secondary branch of the North Anatolian Fault, and two ~4-month long slow slip events beneath western Peloponnese. We find no unambiguous evidence for deep triggered tremor nor for ambient tremor. The absence of triggered tremor at the Hellenic and Calabrian subduction zones supports the less favorable conditions for tremorgenesis in the presence of old and cold slabs. The absence of tremor along the transform faults may be due to an absence of the conditions commonly promoting tremorgenesis in such settings, including high fluid pressures and low differential stresses between the down-dip limit of the seismogenic layer and the Moho.