Solar occultations performed by the Nadir and Occultation for MArs Discovery (NOMAD) ultraviolet and visible spectrometer (UVIS) onboard the ExoMars Trace Gas Orbiter (TGO) have provided a comprehensive mapping of ozone density, describing the seasonal and spatial distribution of atmospheric ozone in detail. The observations presented here extend over a full Mars year between April 2018 at the beginning of the TGO science operations during late northern summer on Mars (Ls = 163°) and March 2020. UVIS provided transmittance spectra of the martian atmosphere in the 200 - 650 nm wavelength range, allowing measurements of the vertical distribution of the ozone density using its Hartley absorption band (200 – 300 nm). Our findings indicate the presence of (1) a high-altitude peak of ozone between 40 and 60 km in altitude over the north polar latitudes for over 45 % of the martian year, particularly during mid-northern spring, late northern summer-early southern spring, and late southern summer, and (2) a second, but more prominent, high-altitude ozone peak in the south polar latitudes, lasting for over 60 % of the year including the southern autumn and winter seasons. When they are present, both high-altitude peaks are observed in the sunrise and sunset occultations, indicating that the layers could persist during the day. Model results from the GEM-Mars General Circulation predicts the general behavior of the high-altitude peaks of ozone observed by UVIS and are used in an attempt to further our understanding of the chemical processes controlling the high-altitude ozone on Mars.

Goundwater investigations are increasingly becoming important for Indonesia. It is natural resources for sustainable development of a region. In this study, PT Sejahtera Alam Energy conducted an investigation of subsurface conditions, especially related to groundwater potential, carried out by a resistivity investigation method by means of Vertical Electrical Sounding (VES) or Geoelectricity in Embung Area, Baturaden Geothermal Project, Pandansari Village, Paguyangan Subdistrict, Brebes Regency. This method is one of the subsurface estimation methods that is considered suitable for water investigations as well as in terms of accuracy as well as in terms of low cost and faster implementation time compared to other geophysical methods.

In an active volcanic arc, magmatically sourced fluids are channeled through the brittle crust by structural features. This interaction is observed in the Andean volcanic mountain belt, where volcanoes, geothermal springs and the locations of major mineral deposits coincide with NNE-striking, convergent margin-parallel faults and margin-oblique, NW/SE-striking Andean Transverse Faults (ATF). The Tinguiririca and Planchón-Peteroa volcanoes in the Andean Southern Volcanic Zone (SVZ) demonstrate this relationship, as both volcanic complexes and their spatially associated thermal springs show strike alignment to the outcropping NNE oriented El Fierro Thrust Fault System. This study aims to constrain the 3D architecture of this fault system and its interaction with volcanically sourced hydrothermal fluids from a combined magnetotelluric (MT) and seismicity survey. The 3D conductivity model and seismic hypocenter locations show correlations between strong conductivity contrasts and seismic clusters in the top 10km of the crust. This includes a distinct WNW-striking seismogenic feature which has characteristics of the ATF domains. As the surveyed region is characterized by high heat flow regimes, volcanic activity and hydrothermal systems related to the volcanic arc, the conductivity contrast suggests that magmatically derived fluids meet an impenetrable barrier, most likely the sealed core of the fault. The resulting increase in hydrostatic fluid pressure facilitates seismic activity on this WNW oriented structure. These results provides the first observation of the mechanism behind the reactivation and seismogenesis of ATF. The study also uncovers the role of the ATF the compartmentalization of magmatic-derived fluids that accumulate to form hydrothermal reservoirs in the SVZ.

In this study, the changes in the occurrence of marine fog over the summer North Pacific in warmer sea surface temperature (SST) or increased CO2 climates were investigated based on atmospheric model simulations by using the fifth phase of the Climate Model Intercomparison Project (CMIP5) multimodel data. Initially, the marine fog representation in CMIP5 multimodels was briefly evaluated globally. We found that the simulated marine fog occurrence was represented relatively well in boreal summer but poorly in other seasons. The results indicated that the changes in the North Pacific high‐pressure system accompanied by changes in horizontal wind patterns control the changes in marine fog occurrence in the North Pacific. The magnitude of contrasting pair changes in marine fog occurrence in the western and eastern North Pacific are primarily determined by the magnitude of changes in the North Pacific high‐pressure system. Global‐scale changes in the vertical profiles of the atmosphere (stability changes) can also affect the marine fog changes. These changes in marine fog over the North Pacific were consistent among most CMIP5 models.

The frequency and intensity of new particle formation (NPF) over remote forest regions in the temperate and boreal zones, and thus the importance of NPF for the aerosol budget and life cycle in the pristine atmosphere, remains controversial. Whereas NPF has been shown to occur relatively frequently at several sites in Scandinavia [1], it was found to be nearly absent at a mid-continental site in Siberia [2]. To explore this issue further, we made measurements of aerosol size distributions between 10 and 300 nm diameter at two remote sites in the transition region between temperate and boreal forest in British Columbia, Canada. The measurements covered 23 days during the month of June 2019, at the time when NPF typically reaches its seasonal maximum in remote mid-latitude regions. These are the first such measurements on the North American continent. Although the sites were only 150 km apart, there were dramatic differences in NPF frequency and intensity between them. At the Eagle Lake site, NPF occurred almost daily and nucleation mode particle concentrations reached above 5000 cm-3. In contrast, at the Nazko River site, there were only 6 NPF events in 11 days and nucleation mode particle concentrations reached only about 800 cm-3. The reasons for this difference are under investigation. They may include airmass origins, pre-existing aerosols, density of forest cover in the surrounding regions, and proximity to the Pacific coast. Our results suggest that measurement campaigns in the remote forest regions of North America to investigate the role of NPF with a more comprehensive set of instrumentation are essential for a deeper scientific understanding of this important process. [1] Nieminen et al., Atmos. Chem. Phys. 18 (2018) 14737-14756. [2] Wiedensohler et al., Atmospheric Environment, 200 (2019) 167-169.

Forecasting relativistic electron fluxes at geostationary Earth orbit (GEO) has been a long term goal of the scientific community, and significant advances have been made in the past, but the relation to the interior of the radiation belts, that is, to lower $L-$shells is still not clear. In this work we have identified 60 relativistic electron enhancement events at GEO to study the radial response of outer belt fluxes and the correlation between the fluxes at GEO and those at lower $L-$shells. The enhancement events occurred between 1 October 2012 and 31 December 2017 and were identified using GOES 15 $>$2 MeV fluxes at GEO, which we have used to characterize the radial response of the radiation belt, by comparing to fluxes measured by the Van Allen probes ECT-REPT between $2.55.0$, and generally similar for $L>4.5$. Post enhancement maximum fluxes show a remarkable correlation for all $L > 4.0$ although the magnitude of the pre-existing fluxes on the outer belt plays a significant role and makes the ratio of pre-to-post enhancement fluxes less predictable in the region $4.0

The influence of aerosol particles on cloud reflectivity remains one of the largest sources of uncertainty in our understanding anthropogenic climate change. Commercial shipping constitutes a large and concentrated aerosol perturbation in a meteorological regime where clouds have a disproportionally large effect on climate. Yet, to date, studies have been unable to detect climatologically-relevant cloud radiative effects from shipping, despite models indicating that the cloud response should produce a sizable negative radiative forcing (perturbation to Earth’s energy balance). We attribute a significant increase in cloud reflectivity to enhanced cloud droplet number concentrations within a major shipping corridor in the southeast Atlantic. Prevailing winds constrain emissions around the corridor, which cuts through a climatically-important region of expansive low-cloud cover. We use universal kriging, a classic geostatistical method, to estimate what cloud properties would have been in the absence of shipping. In the morning, cloud brightening is consistent with changes in microphysics alone, whereas in the afternoon, increases in cloud brightness from microphysical changes are offset by decreases in the total amount of cloud water. We find a radiative forcing in the southeast Atlantic shipping corridor two orders of magnitude greater than previous observational estimates. Approximately five years of data are required to identify a clear signal. Extrapolating our results globally, we calculate an effective radiative forcing due to aerosol-cloud interactions in low clouds of -0.62 W/m2 (-1.23 to -0.08 W/m2). The unique setup in the southeast Atlantic could be an ideal test for the representation of aerosol-cloud interactions in climate models.

VLF auroral hiss at Kannuslehto (KAN), Finland has been analyzed with a reference to progress of 98 isolated magnetic substorms. During 11 winter months of 2015-2018, 91 of them were accompanied by the auroral hiss during the substorm growth phase. No auroral hiss was recorded during the expansion and recovery phases. We found auroral hiss was observed under rising polar cap PC index showing an increasing input of the solar wind energy into the magnetosphere during the substorm growth phase. We also found that KAN was mapped to the vicinity of enhanced Field Aligned Currents (FACs) during the auroral hiss occurrence. For the first time, it was established that the auroral VLF hiss generation in the equatorial part of the auroral oval (KAN location) is a typical signature of a substorm phase.

Soil carbon sequestration has gained traction as a mean to mitigate rising atmospheric carbon dioxide concentrations. Verification of different methods’ efficiency to increase soil carbon sink requires, in addition to good quality measurements, reliable models capable of simulating the effect of the sequestration practises. One way to get insight of the methods’ effects on carbon cycling processes is to analyse different carbon isotope concentrations in soil organic matter. In this paper we introduce a carbon-13 isotope specific soil organic matter decomposition add-on into the Yasso soil carbon model and assess its functionality. The new 13C-dedicated decomposition is straightforward to implement and depends linearly on the default Yasso model parameters and the relative carbon isotope (13C/12C) concentration. Despite of their simplicity, the modifications considerably improve the model behaviour in a 50-year long simulation.

In the process of a fluvial evolution, the water discharge, sediment charge and stream energy expenditure dominant the channel patterns of a river. Given water and sediment, an alluvial channel is self-organizing, adjust to achieve a stable equilibrium state, and form a characteristic channel geometry (channel width, depth and slope). In the equilibrium condition which is also said to be in regime or graded, the flux of the water and sediment from the watershed should be equal to the flux of the downstream channel(s). By studying bed load transportation and stream power conversion on a steady and uniform stream, we suggest two characteristic parameters that are energy conversion length and regime transportation length of sediment. The regime equation and equations of fractal features are set here. All cross-section variables (stream width, depth and velocity) of a regime stream, who theoretically derived under the equilibrium of sediment transportation and the conversion of stream power, are exclusively determined by the two lengths and the water discharge.

Autonomous large-scale detection of whistler-ode chorus elements in the Van Allen radiation belts has been an open computational challenge. This is primarily due to: (i) Variability of the spectral morphology of chorus elements, and (ii) Structured background interference from hiss-like chorus that can make elements difficult to detect using traditional signal processing and pattern recognition techniques. We will present computational techniques drawing on pixel connectivity, signal-to-noise (SNR) considerations as well as supervised and unsupervised pattern recognition techniques. Specifically, we will explore the efficacy of popular machine learning techniques trained on unfiltered spectral images versus those trained on culled features generated by unsupervised feature extraction techniques. Representative results will be presented based on magnetic field measurements taken by the EMFISIS instrument suite in the Van Allen probes mission.

The mechanical coupling between a planet and its atmosphere enables the conversion of seismic waves into infrasound waves, i.e. low-frequency pressure perturbations (< 20Hz), which propagate to the upper atmosphere. Since the characteristics of the seismically-induced pressure perturbations are connected to their seismic counterparts, they provide a unique opportunity to investigate the atmospheric and interior structures of a planet or to constrain source properties. However, in Earth’s remote regions, deploying seismic or infrasound networks at the surface can be a difficult task. Stratospheric balloon platforms equipped with pressure sensors have therefore gained interest since they provide a unique and inexpensive way to record pressure signals in the atmosphere with a low noise level. Yet, infrasound observations of Earthquakes on balloon platforms have never been reported in the literature. In this study, we investigate the seismo-acoustic wavefield generated by the aftershocks of the 2019 Ridgecrest sequence and other regional low-magnitude Earthquakes on July 22 and August 9, 2019 using four free-flying balloons equipped with pressure sensors. We observed a strong signal coherence after the largest event between seismic motions at the surface and balloon pressure variations which matches our numerical simulations. A first atmospheric earthquake detection is crucial to demonstrate the viability of this novel technique to monitor infrasound from natural and artificial seismicity on Earth, and the study of seismic activity on planets such as Venus.

Communities in Fiji rely on provisioning services from landscape resources such as agricultural and forestry-related production, and climate regulation determined by the mix of landscape resources across space. Accurate mapping and monitoring of patterns of land use and land cover (LULC) over time at scales relevant to livelihood processes is important for informing landscape management, land use policies, and climate-smart sustainable development. A methodology developed collaboratively with landscape stakeholders to produce an inter-annual LULC map that addresses natural resource, agricultural, and forestry management use cases is presented here. Key requirements identified by stakeholders were that the LULC methodology was robust, relatively easy to reproduce, and could be applied to other Fijian landscapes with different dynamics. Using publicly available remotely sensed data and geospatial tools, we applied the LULC methodology for two locations in the Ba Catchment, Fiji. Field orientation and key validation data were collected using the QField open-source mobile GIS, and labelled training and accuracy assessment data were collected in Google Earth. Annual median multispectral surface reflectance and seasonal NDVI-based phenology metrics derived from Sentinel-2, and topographic variation from SRTM DEM provided the best discrimination between vegetation classes across the catchment from low-lying coastal areas to the highlands (> 1000 m ASL). A random forest model was trained and validated in Google Earth Engine to produce an inter-annual LULC map with a 10m spatial resolution. An important outcome from our work was the transfer of skills and building of local stakeholder capacity to continue to update the LULC map, and to expand the map to include other communities, catchments and forestry areas across Fiji. This capacity building included iterative stakeholder consultation, co-development of online training materials, workshops, and collaborative fieldwork.

Time series prediction involves learning existing observation data of a parameter and predicting its future evolution, with applications in many fields. Based on a machine/deep learning method, it is useful to predict the evolution trend of microseismic parameters during rockburst development. Our study explores key microseismic indices that help describe the development process of rockbursts based on abundant rockburst data obtained from deep underground engineering activities. On this basis, the structure of a deep convolution neural network is modified, and its input and output modules are improved, to realize a univariate, multivariate input and a single-step, multi-step output. Finally, various new models of the microseismic multi-parameters for time series prediction are proposed, including a univariate prediction model, a multiple parallel series model, a multiple input series model, and a multivariate multi-step prediction model. Model training, testing, and interpretation of the rockburst risk and a comparative analysis of the different models are carried out for the complete process of multiple rockburst disasters. The results show that the proposed models can predict the evolution trends of various key characteristics during a rockburst and ensure the timeliness and accuracy of rockburst risk prediction. They provide a new research idea for the prediction and early warning of rockburst disasters in deep underground and mining engineering.

We develop a new, wind-driven lake spray aerosol (LSA) emissions parameterization that resolves both particle size and chemical composition, and investigate the impact of these emissions on regional chemistry in the Great Lakes region. We conduct WRF-Chem simulations for November 2015, a time period with high LSA emissions. LSA particles emitted from the surface of the Great Lakes increase particulate NO$_{3}^{-}$ by 46\% over the Great Lakes and by 16\% over land, primarily due to heterogeneous reactions between CaCO$_{3}$ and HNO$_{3}$. Cations emitted from lake spray affect the thermodynamic equilibrium, reducing particulate NH$_{4}^{+}$ by 42\% over the Great Lakes and by 6\% over the surrounding land. This also influences gas-phase species in the region, decreasing nitric acid by up to 71\% over lakes. Overall, these simulations suggest that understanding LSA and its impact on other air pollutants is important for determining health and climate effects in the Great Lakes region.

Laboratory data are essential for testing and refining of theories and models in Earth sciences. Recent developments in data mining techniques and machine learning have made it feasible to utilize and digest large amounts of information; yet such data must be initially prepared and structured in a meaningful way. Recognizing the potential and challenges of data access, multiple efforts are underway in the development of digital data repositories (Strabospot, Epos). Currently most information in experimental Geophysics is not accessible in digital, searchable form. Such information may include: equipment capabilities and configurations, original and edited experimental data, laboratory calibrations as well as information regarding testing protocols and procedures. The LAPS project aims to design and develop resources to facilitate data workflow and access. It specifically focuses on the needs of laboratory researchers, students and managers to prepare data for use in digital data repositories. As laboratories use a wide variety of hardware and software solutions to acquire and process data, we focus our efforts on the development of web based tools that do not require specific local infrastructure and software. One of the main objectives of LAPS is to establish a coherent and effective way to describe equipment and experiments across a variety of testing rigs and devices. To simplify the workflow we are proposing a combination of selecting pre-configured equipment and experimental profiles and manual data entry via web form. A completed test protocol containing all experimental metadata may then be saved locally (e.g., as JSON file) or (optionally) to a database. Such test protocols can be re-loaded and modified as needed. To complete the workflow of a successful test, a link to original or processed data files may be inserted. The data file layout can be defined in the experimental profile. Upload to a digital data repository is optional but by adhering to the proposed Strabo/Epos data model it will not require additional input. While the web based workflow will be accessible to all users, we also recognize the need to integrate the system into specific work flow solutions in rock deformation laboratories. We therefore provide the framework that simplifies local data management systems and analytical applications.

Velocity is one of the fundamental data obtained from seismic and it is the direct behavior of the solids and fluids in lithosphere. Here we present an analysis of the derivative gradient of seismic velocity which can help identify the featured boundary of favorable petroleum accmulations such as sedimentary facies boundary, faults, and flow unit edges. The derivative gradient can be calculated both horizontally and vertically, thus it can help discriminate favorable targets in three-dimensional. We find the application of derivative gradient to detect or enhance edge is relatively mature in gravity and geomagnetic analysis but rarely mentioned in seismic nor in petroleum exploration. We believe we can make better use of the seismic velocity data by this means as it is quite efficient in pinpointing the favorable petroleum targets in subsurface with precisions of tens-of-meter scale, depending on the horizontal resolution of seismic survey.

The SEIS seismometer of the InSight mission was deployed on the ground of Elysium Planitia, on 19 December 2018. Interferometry techniques can be used to extract information on the internal structure from the autocorrelation of seismic ambient noise and coda of seismic events. In a single-station configuration, the zero-offset global reflection of the ground vertically below the seismometer can be approximated by the stacked ZZ autocorrelation function (ACF) for P-waves and the stacked EE and NN ACFs for S-waves, assuming a horizontally layered medium and homogeneously distributed and mutually uncorrelated noise sources. We analyze continuous records from the very broadband seismometer (SEIS-VBB), and correct for potential environmental disturbances through systematic preprocessing. For each Sol (martian day), we computed the correlations functions in 24 windows of one martian hour in order to obtain a total correlation tensor for various Mars local times. In addition, a similar algorithm is applied to the Marsquake waveforms in different frequency bands. Both stability analysis and inter-comparison between background noise and seismic event results suggest that the background seismic noise at the landing site is reliably observed only around 2.4 Hz, where an unknown mechanism is amplifying the ground shaking, and only during early night hours, when the noise induced by atmospheric disturbances is minimum. Seismic energy arrivals are consistently observed across the various data-sets. Some of these arrivals present multiples. These observations are discussed in terms of Mars’ crustal structure.