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.

Surveying the seafloor with new technologies and techniques provides a new generation of higher-resolution imagery of both bathymetry and benthic habitat. Recent surveys using an Edgetech 4600 interferometric sonar have identified previously unknown patterns in these properties in the estuarine and nearshore areas in coastal Georgia, USA. As part of a multi-year mapping effort, four of the seven sounds in coastal Georgia have been mapped: Wassaw Sound, Ossabaw Sound, St. Catherine’s Sound and Sapelo Sound. Interferometry, sidescan sonar imagery and bottom sediment character have been combined to identify bathymetric patterns, diverse benthic habitats and to produce comprehensive habitat maps. Although the distribution of habitat types differs within each of these sites, all habitat types are common to all areas, and some general patterns emerge. Each site exhibits regions of mobile sediments, but of critical importance, also exhibits deep scours into semi-indurated materials that create vertical relief and hard substrates. Each project area can be divided into geomorphological features i.e., channels, deep depressions, vertical walls, ridges and flats. Bedforms are commonly visible, particularly in channels and depressions. Sediments are dominated by sand. These data, along with derivatives e.g., slope, rugosity and bathymetric position index, identify potentially important, complex habitat for sessile and mobile organisms. Scarps and ledges (up to 2 m high, up to 1000 m long) are distinctly recognizable in the sidescan imagery and slope analysis. This presentation will describe the procedures for working with shallow water interferometric sonar data and interpretations that can be reached using these tools.

The 2018 eruption of Kīlauea Volcano included caldera collapse at the summit of the volcano that was well recorded by a network of both permanent and temporary seismometers and infrasound microphones. Volcanic activity prior to the start of the eruption was elevated, including high lava lake levels and increased seismicity. Deflation of the summit began shortly after the eruption in the lower East Rift Zone commenced and was accompanied by a drop in the summit lava lake, which eventually disappeared from view after lowering by several hundred meters. Continued volume loss from beneath the summit eventually led to caldera collapse, which was accompanied by increases in earthquake rates and tremor amplitudes. Infrasonic tremor that originally rose from spattering at the surface of the lava lake was replaced by discrete infrasonic events arising from rockfalls and slumps. On May 16, the first of tens of collapse events occurred, beginning a cycle of increasing earthquake rates and energy release in the presence of deflation. After an initial increase in rate, seismicity rates remained constant for several hours prior to the next collapse event. Earthquakes during these events were typically part of repeating earthquake families and occurred on one of several circumferential cracks that marked active collapsing blocks. Through time, earthquake activity has mirrored the morphology of the collapse, migrating primarily north and east as caldera down drop extended in those directions. Collapse-related infrasound arrivals were initially down, suggesting downdropping of the surface, followed several seconds later by higher frequency infrasound, which we interpret to reflect the explosive or expulsion phase reaching the surface. Infrasound signals were 2-3 times more energetic below 0.5 Hz than above. Especially after May 29, when caldera collapse became much larger in surface area, infrasound signals were highly repetitive with a strong downward first motion. The collapse events were also deficient at seismic frequencies > 0.5 Hz, compared to typical tectonic earthquake sources. Despite similarities in waveforms at low frequencies (<0.1 Hz) and in infrasound, the seismic waveforms at high frequencies were not similar, reflecting either a unique source in each collapse event or a change in location.

Despite much field and laboratory research, the origin of calcification in coccolithophores remains indeterminate. While most experiments on living species are not applicable to extinct taxa, long-term morphologic changes in lineages under well constrained oceanographic conditions may help elucidate the primary forcing on coccolithophore evolution if examined in the context of fundamental requirements (e.g., nutrient availability) of the living cell. The Order Discoasterales (66–1.92 Ma) was among the most prolific (>600 species, 16 genera) with greatest abundance and diversity in warm oligotrophic waters. Their coccoliths tell a story of morphologic changes that affected also their constituent elements resulting in lightweight constructions that became increasingly cavernous as oligotrophy increased in the Paleocene ocean, leading to increase in surface/volume ratio in keeping with increase in cell size. This likely constitutes direct evidence that coccoliths were involved in regulating cell physiology, both by maintaining a sufficient surface for nutrient absorption when cell volume increases or when nutrient content in seawater decreases, and by determining sinking rates. The cavernous nature of coccoliths further suggest mixotrophic physiology. Calcification may thus have been the innovation permitting the migration of the ancestral coccolithophore from nutrient-rich coastal waters to the blue ocean.

The Baltic Sea is a shallow, stratified, brackish water sea with several subbasins. In this work, we analyzed CTD casts from HELCOM monitoring data of the Baltic Sea, data from FMI's glider missions in 2016 and 2017 and profiles from FMI's Argo floats. We used clustering and machine learning algorithms developed for time series analysis to classify vertical profiles. We endeavored to classify profiles into classes with similar shapes. Then, we defined whether it was possible to define the depth of the upper mixed layer and possible halocline depth in each of these classes. Our results show that time series classification algorithm can cluster vertical profiles of CTD temperature and salinity and classify them according to sea area and season.

We introduce a computer program for time series tuning and analysis. The well known in paleo-climatic community program AnalySeries after Paillard et al. is restricted to the Mac OS (32-bit) and, according to Apple plans to move entirely onto the 64-bit system, it will not be supported in the future upgrades of Macintosh OS. QAnalySeries is an attempt to re-implement the major functionality of AnalySeries thus providing the community with a useful tool. QAnalySeries is written using Qt SDK as a free software and can be run on Macintosh, Windows and Linux systems. Paillard, D., L. Labeyrie and P. Yiou (1996), Macintosh program performs time-series analysis, Eos Trans. AGU, 77: 379.

We analyze changes in vegetation greenness across the coastal, Andean, and Amazonian regions of continental Ecuador, 1982-2010. Using Normalized Difference Vegetation Index (NDVI) anomalies derived from the Advanced Very High-Resolution Radiometer (AVHRR) on monthly and annual bases, we identify: i) long-term changes in annual NDVI, ii) seasonal shifts in greenness patterns, and iii) spatial patterns of change in vegetation greenness. Results indicate overall significant greening, or NDVI increase, after the mid-1990s, with distinct seasonal and regional variations. In the Amazon changes occur between September and February, resulting in a prolonged growing season during the later period. Significant increases are witnessed in coastal regions between February and May, but with no change in growing season. Fluctuations in NDVI in the Andes mimic the coast in the western slopes and the Amazon in the eastern slopes but exclude major changes in NDVI. The research investigates the possible effects of precipitation and CO2, and contributes to the understanding of tropical vegetation change in a rapidly changing environment.

The Vector Electric Field Instrument (VEFI) aboard the CNOFS satellite recorded over 20 thousand 12-s-duration, 3-axis continuous VLF waveforms syncronously on 3 crossed antenna booms. Tbis provides an important data archive on Poynting flux and wave intensity, of relevance to wave-particle interactions in tbe low-latitude inner plasmasphere. We will provide a summary of all the observations, not limited to discrete whistlers associable with known lightning events (our focus in previous reports).

Over-pumping and extended drought events have raised awareness on groundwater resources management within the Mediterranean Basin. As groundwater often has an important role in sustaining certain types of aquatic, terrestrial and coastal ecosystems, water policy makers should pay special concern to maintain groundwater contribution to the environmental flow. To this aim, the present study focuses on the assessment of a newly introduced groundwater management tool, the Groundwater Footprint (GWF) (Gleeson et al., 2012). GWF represents a water balance between aquifer inflows and outflows, focusing on environmental flow requirements and expresses the area required to sustain groundwater use and groundwater dependent ecosystem services. GWF is applied to a pilot aquifer in the Mediterranean Basin, crossed by an intermittent river. Total abstraction, natural and artificial recharge, groundwater contribution to environmental stream flow are the critical parameters related to GWF estimation. In order to estimate groundwater contribution to the environmental stream flow, the assumption that groundwater contributes to the environmental flow to the same percentage as baseflow contributes to the natural flow has been made. However, the main constraint met in GWF estimation has been the estimation of the environmental flow in non-perennial river, as the quantification of the environmental flow requirements has been mainly studied for perennial rivers. For this reason, the available to the literature studies referring to environmental flow requirements have been assessed and the most appropriate method for the specific pilot area has been applied. The ratio GWF to the actual area of the aquifer (A) can be used to assess groundwater management, as GWF/A>1 indicates unsustainable groundwater consumption. Consequently, GWF/A may consist a comprehensible to the general public groundwater stress indicator and can be used to raise awareness.

Differential Interferometric Synthetic Aperture Radar (DInSAR) based mapping of surface deformation has proven valuable in a variety of geoscience applications. Conventional approaches to DInSAR analysis require significant expertise and are not suited to addressing the opportunities and challenges presented by the large multi-temporal SAR datasets generated by future radar constellations. As a result, the Canada Centre for Mapping and Earth Observation (CCMEO) developed, in support of Natural Resources Canada and Government of Canada priorities, a system for automatic generation of standard and advanced deformation products based on DInSAR technology from RADARSAT Constellation Mission (RCM) Synthetic Aperture Radar (SAR) data. Existing RADARSAT-2 processing algorithms were adapted to RCM specifications and novel advanced processing algorithms were developed to address the large data sets resulting from the constellation’s four-day rapid revisit cycle. This permitted expanding the DInSAR functionality across a wide-range of spatial and temporal scales. The system architecture is scalable and can be expanded to serve a large number of clients; it can simultaneously address multiple application areas including natural and anthropogenic hazards, natural resource development, permafrost and glacier monitoring, coastal and environmental change and wetlands mapping.

The gap between governmental policy and actions taken by local officials often exists and this gap could be even more severe when it is climate adaptation policy. On the other hand, most of existing studies tend to pay more attention to the structure and the performance of the model rather than the practical operation procedure. To minimize the gap and to evaluate the effectiveness of the adaptation policy, a cross-scale and cross-sector adaptation assessment model, Agriculture and Hydrology assessment model (AgriHydro), is proposed in this study. AgriHydro is established physically to embed top down policies and bottom up local actions and combine with the standard assessment framework, Climate Adaptation 6-Steps and Climate Risk Template, to support decision-making. For sub-models of the AgriHydro, the Aquacrop crop model and the system dynamic water distribution model were calibrated and integrated to form the feedback mechanism. The weather generator (WthGen) modular including climate change scenarios is also established and coupled into the AgriHydro to form a fully functional adaptation assessment tool. An actual application for analyzing the adaptation policy for water supply and crop yield in Taoyuan City of Taiwan is implemented due to the diversity and the complexity of Taoyuan City in land use and water system. The results reflect the possible trade-off of future risks between water resource and agriculture fields under different climate and social scenarios. Moreover, this study shows that the proposed model can provide the linkage to the standard assessment framework, which allows a consist understanding among users on risk and model output. This enables AgriHydro to become a practical and operational tool for decision making and ready for further application.

Radio science experiments for planetary geodesy or tests or relativistic gravity involve precise measurements of the spacecraft range rate enabled by two-way microwave links. Since the uncertainty on the estimated parameters depend almost linearly on the noise in the radio link, finding ways to reduce disturbances is essential for best scientific results. Tropospheric and antenna mechanical noises, among the leading noise sources in two-way Ka-band radio links, could be reduced using a suitable combination of Doppler data collected at the two-way antenna and at an additional, smaller and stiffer, three-way antenna [1]. The Time-Delay Noise Cancellation technique (TDMC) can provide significant reduction of the measurement noise if the listen-only antenna is located in a site with particularly favorable tropospheric conditions. This noise-reducing technique has only been tested by artificially producing a large mechanical noise event at the two-way antenna and using a similar three-way antenna to cancel the disturbance. We report on a practical demonstration of the capabilities of the TDMC technique applied to Doppler data from Cassini spanning 2004 through the last Titan gravity flyby in 2016. The tracking configuration in those passes was not tailored for the use of the TDMC, therefore the technique proves to be effective only with favorable noise conditions. Nonetheless, for those passes where tropospheric or antenna mechanical noises were relevant, we find substantial noise reduction. For example, Doppler data from the Titan-122 gravity flyby processed with the TDMC show about a factor-of-three noise reduction (at 60-s integration time) with respect to the two-way link. These results suggest that the choice of the three-way antenna and the scheduling of the tracking passes are crucial parameters that should be considered to fully exploit the improvement in accuracy provided by the TDMC technique. [1] Armstrong, J. W. et al., Radio Science 43 RS3010 (2008)

The use of geophysical methods to characterize subsurface properties has significantly grown in the last decade. Although geophysics can bring relevant spatial and temporal information on subsurface processes, the quantitative interpretation and integration in models remain difficult. Indeed, standard deterministic solutions suffer from (excessive) smoothing and spatially variable resolution, whereas joint or coupled inversions remain difficult to apply in complex cases. Hermans et al. (2016) proved using cross-borehole ERT that physical properties distribution could be directly retrieved from data using Bayesian Evidential Learning (BEL). BEL uses a series of prior models to derive a direct relationship between data and forecast in a reduced dimension space. This can be challenging when the prediction becomes more complex with higher dimensions. In this contribution, we extend the work of Hermans et al. (2016) to a full 4D experiment (3D + time). We demonstrate that the shape and amplitude of the temperature plume can be retrieved, with uncertainty quantification, during a push-pull experiment using surface ERT. We analyze the robustness of the solution using a synthetic benchmark. The results indicate that the median of the posterior is very close to the true temperature distribution. The relative error increases at the edge of the temperature plume where the change of temperature is limited. This is related to the limited resolution of geophysics and the process of dimension reduction. We also investigate how discrete cosine transform can improve the dimension reduction process without altering the final prediction. Finally, we show that BEL is able to retrieve the spatio-temporal variability of the plume, while the smoothness constraint inversion fails to accurately image the corresponding contrast, largely underestimating the amplitude of the temperature change. BEL is therefore a well-suited framework for the interpretation of 4D geophysical data avoiding the drawbacks of standard deterministic solutions. Hermans, T., Oware, E., & Caers, J. (2016). Direct prediction of spatially and temporally varying physical properties from time-lapse electrical resistance data. Water Resources Research, 52, 7262-7283.

Sand production is the process in which formation sand and gravel would migrate into the wellbore by the flow of reservoir fluids. This is a problem that endangers the safety of hydrate exploitation. The aim of this study is to understand sand production in during hydrate exploitation. A novel experimental apparatus was constructed to examine sand production in the hydrate-bearing sediments by applying the depressurization method. The maximum pressure of apparatus is 30 MPa, the temperature could be controlled from -253.15 to 313.15 K. The pore pressure, crustal stress, production pressure, gas flow rate, water production volume and subsidence rates could be measured. The vertical wellbore comprised liner 1 (ø32 mm × 135 mm, 3 mm holes, arrangement: 36°, holes row gap: 10 mm) and liner 3 (ø24 mm × 135 mm, 2.5 mm holes, arrangement: 36°, hole row gap: 10 mm) with a sand screen. Besides gas in from top, the sediment chamber (ø158 mm × 120 mm) had a middle mesh screen that allowed gas and water enter or vacuumize the chamber circumferentially around the sediments (ø158 mm × 100 mm). Sand production situation was recorded by HD camera through the visual window on the gas-solid-liquid separator. Hydrate production was divided into three periods: water, gas with water drops, and gas. We found fine sand production in the first period and sand grains production in the second. The sand production behaviours through the different gas production rates in two production method - depletion gas production curve and stable gas production curve were discussed. The grain sizes of sand production were increasing in the production period with hydrate saturation decreasing. The temperature related characteristics of the hydrate layers differed during different stages of hydrate production. The unique sputtering occurring owing to the decomposition of the hydrate might have provided the driving force for sand migration, and water gas bubbles or gaseous water drops from the decomposed hydrate might have enhanced sand carrying capacity. The subsidence of hydrate-bearing sediments was influenced by sand production, whereas the maintenance of crustal stress possibly influenced the rate and magnitude of subsidence. The stimulation at late production in low hydrate saturation might conduct the subsidence and sand production increased dramatically.

Bridge foundation scour is the most common cause for the failure of highway bridges. The assessment of local scouring mechanism around bridge piers provides information for decision-making regarding the pile footing design, predicting the safety of bridges under critical scoured conditions, and as a result, may help prevent unnecessary loses. Since scour in bridges is the water-induced erosion of soil particles around bridge foundations, the loss of lateral load capacity at bridge foundations may induce bridges to become highly vulnerable to failure when the effects of scour and floods are combined. In this study, high definition 3D models of the flood plain and the amount of current scour in bridge piles were acquired by Unmanned aerial vehicle (UAV) based measurements which provide a practical approach and bring high precision solutions considering traditional measurement systems. The present study evaluated the performance of bridges with reinforced concrete (RC) pile foundations under the effects of local scour and flood. Thus, a RC bridge constructed over Boğaçayı in Antalya, Turkey was selected as the case study. The vulnerability of the bridge was assessed under flood loading considering the predicted scour amount. The maximum flood loads according to different return periods (5, 20, 50, 100 and 500 years) and the corresponding maximum scour depths were determined by HEC-RAS software. As a result, the outputs were regarded as input parameters for the evaluation of lateral behavior of the bridge under consideration. The soil-pile foundation-structure interaction was implemented in the finite element models of pile groups. The multi-hazard performance of the bridge was evaluated under the maximum predicted scour depth and corresponding flood load. In conclusion, as the scour depth increased the fundamental periods, shear forces and the bending moments were observed to increase while the pile lateral load capacities diminished. Therefore, it was ascertained that the scour substantially deteriorated the performance of the bridge under multi-hazard environment.

Unmanned Aerial Vehicle (UAV) based Structure-from-Motion (SfM) techniques have renovated 3D topographic monitoring of earth surface, offering low-cost, rapid and reliable data acquisition and processing. Multi-temporal models of the river environment can be produced by autonomous operation in order to determine erosion, subsidence, landslide, soil transport and surface deformation in the riverbeds. Herein, the acquisition of repeated topographic surveys helps us to characterize the flow regime and to monitor the sediment dynamics. This study presents the hydromorphological changes of the meandering structures by using UAV-generated point clouds and Digital Surface Models (DSMs) produced by SfM at different times in the Büyük Menderes Basin located in the western part of Turkey. The processing of the data obtained with the flights were made in January and June 2018 at selected three meander locations with the highest visible changes according to the long-term satellite imageries. Especially, riverbank erosion along the river was determined by digitizing the edges and volumetric calculations of the eroded/deposited sediments derived from UAV-based measurements. In addition to the periodic volumetric differences of the meander structures, the differences in volumetric comparison methods for the same meander structures have been evaluated. Ultimately, the sediment profiles were extracted along the river banks at the selected part of the meanders and the amount of deposited sediments were determined to increase in a range between 1.5% and 3.3% of the total sediment. In conclusion, it is estimated that UAVs will be used instead of conventional photogrammetry aircraft in many future projects, considering the data production times and costs in large areas. Further, various digital cameras and sensors can be mounted on UAVs in order for examining the sediment effect on the health and productivity of plants in agricultural areas around the meanders.

Groundwater occurrence in crystalline basement complex is mainly due to the development of secondary porosity and permeability arising from the weathering and fracturing of the low porosity igneous and metamorphic basement rocks. In this study, geophysical survey involving seismic refraction and 2D electrical resistivity tomography (ERT) was conducted to assess the hydrogeological characteristics of the weathering profile of the crystalline basement rocks in Olomore, Abeokuta, southwestern Nigeria. The 2D ERT survey was conducted along five Traverses using dipole-dipole array with a minimum electrode spacing of 5.0 m in Traverses 1, 2, 3 and 5, and 10.0 m in Traverse 4, and a dipole separation factor of 1 – 4 in all the traverses; the observed apparent resistivity data were inverted using RES2DINV. The seismic refraction survey was conducted along the same traverses using 10 Hz electromagnetic geophones; the refraction data were processed using SeisImager with the first arrival travel times picked using Pickwin module and inverted using Plotrefa to obtain velocity model of the subsurface. A good correlation exists between the 2D ERT images and the seismic refraction velocity models. The effective depth of investigation for both ERT and seismic refraction is approximately 43.0 m in all the traverses except for ERT of Traverse 4 which 66.0 m depth of investigation. Four lithologic layers may be inferred with varying model resistivity and P-wave velocity range of 546-974 m/s, 1456-1877 m/s, 2042-2944 m/s, and 3041-6894 m/s respectively. Both ERT and seismic refraction images indicate that the regolith (collapsed zone and saprolite) is relatively thin (< 10.0 m) and may be unable to support adequate drawdown for good yield. But the weathered and fractured basement is sufficiently thick to support adequate drawdown for high groundwater storativity and yield; depth-to-bedrock is greater than 20.0 m in most part of the study area. The study shows that the combination of ERT and seismic refraction is effective for near-surface characterisation for hydrogeological investigations in crystalline basement complex.