Reusing produced water for hydraulic fracturing simultaneously satisfies challenges of fresh water sourcing and the design/operation of an extensive disposal well infrastructure. This presentation provides an overview of a reuse program from concept through implementation including qualification of advanced water recycling technologies. We target the most prolific unconventional reservoir play in the United States – the Permian Basin. Sourcing water for full-field development therein represents a significant problem since it is in short supply in (semi)arid regions of West Texas and Southeastern New Mexico. We report results from a synergistic industry-academia collaboration wherein desalination pretreatment was first evaluated at lab scale to (i) systematically evaluate partial softening (i.e. “floc-and-drop”) versus neutral pH oxidation for iron removal (ii) investigate synergistic effects of FeCl3 and polymer addition to destabilize colloids (including particulate iron) and induce high-rate sedimentation and (iii) develop and implement robust techniques using video and image analysis to characterize process performance and floc properties (e.g. morphology, size, and settling velocity). Jar tests and associated measurements were completed in the range 4 - 44 ºC covering the range of temperatures measured in the Permian. FeCl3 in conjunction with an anionic polymer dramatically improved colloid destabilization and floc growth via enmeshment of primary colloids by amorphous iron precipitates and inter-particle bridging by the adsorbed polymer. Larger, stronger, and denser flocs thus formed settled extremely rapidly without breakage (i.e. high rate sedimentation). Bench-scale results were integrated in the design and testing a 5,000 BPD pilot scale high-rate clarifier. Pilot scale results show that the neutral pH method of clean-brine generation produced 5-10 times less sludge while achieving 15-20% higher throughput over the alternative floc-and-drop method. Both bench- and pilot-scale findings were incorporated in design and operation of a 50,000 BPD full-scale reuse facility in the Permian Basin. This presentation will share lessons learned from operating a large-scale reuse facility and how academic research can inform and be motivated by industrial practices (and vice versa).

We conduct the first 4D-Var inversion of NH3 accounting for NH3 bidirectional flux, using CrIS satellite NH3 observations over Europe in 2016. We find posterior NH3 emissions peak more in springtime than prior emissions at continental to national scales, and annually they are generally smaller than the prior emissions over central Europe, but larger over most of the rest of Europe. Annual posterior anthropogenic NH3 emissions for 25 European Union members (EU25) are 25% higher than the prior emissions and very close(<2% difference) to other inventories. Our posterior annual anthropogenic emissions for EU25, the UK, the Netherlands, and Switzerland are generally 10-20% smaller than when treating NH3 fluxes as uni-directional emissions, while the monthly regional difference can be up to 34% (Switzerland in July). Compared to monthly mean in-situ observations, our posterior NH3 emissions from both schemes generally improve the magnitude and seasonality of simulated surface NH3 and bulk NHx wet deposition throughout most of Europe, whereas evaluation against hourly measurements at a background site shows the bi-directional scheme better captures observed diurnal variability of surface NH3. This contrast highlights the need for accurately simulating diurnal variability of NH3 in assimilation of sun-synchronous observations and also the potential value of future geostationary satellite observations. Overall, our top-down ammonia emissions can help to examine the effectiveness of air pollution control policies to facilitate future air pollution management, as well as helping us understand the uncertainty in top-downNH3emission estimates associated with treatment of NH3surface exchange.

The demise and closure of the Neotethyan Ocean gave way to the collision and finally amalgamation of various continental fragments in Turkey along the Izmir-Ankara-Erzincan and Intra-Tauride suture zones. These continental fragments include Pontides in the north and Menderes-Tauride , and Kırşehir Block in the south. This study aims to the restoration of these suture zones in central Anatolia using paleomagnetic tools during Neogene. Most of the paleomagnetic studies carried out in the region consider the deformation of Anatolian Block as a monolithic block rotated counter-clockwise due to escape tectonics since the Miocene. We introduce new paleomagnetic evidence obtained from Neogene sedimentary successions and few volcanic suits. Our results point out five distinct tectonic domains with distinct rotation patterns that indicate the rotational deformation of Central Anatolia is far more complex than generally presumed. Among these, 1) Kırıkkale-Bala Domain (KB) is rotated ~18° clockwise, 2) the Tuz Gölü Domain (TG) underwent ~15° counter-clockwise rotation, 3) the Alcı-Orhaniye Domain (AO) rotated ~25° counter-clockwise sense, 4) the Haymana Basin is divided into two different domains, (4) the Northern Haymana Domain (NHY) underwent ~17° counter-clockwise rotation while (5) the Southern Haymana Domain (SHY) underwent barely no net rotation (~5° clockwise) since the early Miocene. The Kırşehir Block was proposed to be an NNE-SSW striking tectonic block that broken into three fragments. These fragments underwent clockwise, in the north, and counterclockwise rotations in the south, respectively, during early Tertiary due to collision and N-S shortening of the Kırşehir Block between Taurides and the Pontides.

Seismic-frequency torsional forced-oscillation measurements of shear modulus dispersion and associated strain-energy dissipation under conditions of simultaneously high temperature and pressure in our laboratory require the specimen to be enclosed within a thin-walled metal sleeve – typically of mild steel. However, the well-known transition between the austenite and ferrite phases on cooling across the interval 900-700ºC complicates its mechanical behaviour. The resulting uncertainty tends to mask the seismologically important onset, within this temperature range, of appreciably anelastic behaviour of polycrystalline olivine. In order to more closely document this important transition in mechanical behaviour, we have conducted an unpublished study in which of a specimen of polycrystalline olivine is jacketed within a copper sleeve which retains its face-centred-cubic (fcc) structure throughout the range of the measurements limited to 1050ºC by the proximity of the melting point. Here we report measurements to higher temperature (1200ºC) in which we employ austenitic (fcc) stainless steel (SS) as an alternative jacket material. Two parallel reference experiments with a SS-jacketed SS specimen and a SS-jacketed sapphire specimen were also conducted to obtain the mechanical properties of the jacket material. Such information concerning the viscoelastic behaviour of SS is used to subtract the torsional stiffness of the SS jacket from the properties of SS-jacketed olivine and thereby isolate the mechanical behaviour of olivine. The resulting dissipation spectrum for the olivine specimen consists of a monotonic background dissipation with a superimposed peak located within the 1-1000 s period range for temperatures between 900 and 1050ºC. The dissipation peak and associated shear modulus dispersion, potentially attributable to elastically accommodated grain boundary sliding, display an Arrhenius dependence upon temperature - moving systematically to shorter periods with increasing temperature. Comparison of the results obtained for sol-gel Fo90 olivine specimens enclosed within the alternative mild-steel, copper, and stainless-steel jackets will provide new insight into the nature of the seismologically important transition between the elastic and anelastic regimes.

Deep water formation (DWF) in the North Western Mediterranean (NWMed) is a key feature of Mediterranean overturning circulation. Changes in DWF under global warming may have an impact on the regional and even on the global climate. Here we analyze the deep convection in the Gulf of Lions (GoL) in a changing climate using an atmosphere-ocean regional coupled model with a high horizontal resolution enough to represent DWF. We find that under the RCP8.5 scenario the NWMed DWF collapses by 2040-2050, leading to almost a 90% shoaling in the winter mixed layer depth by the end of the century. The collapse is mainly related to changes in sea water temperature and salinity of Modified Atlantic Water (MAW) and Levantine Intermediate Water (LIW) that strengthen the vertical stratification in the GoL. The stratification changes also alter the Mediterranean overturning circulation and the water, heat and salinity exchange with the Atlantic.

Remotely sensed solar-induced fluorescence (SIF) has emerged as a novel approach for terrestrial vegetation monitoring. The in situ continuous optical remote sensing tool in conjunction with concurrent eddy covariance (EC) flux measurements provides a new opportunity to advance terrestrial ecosystem science. Here we introduce a network of ground-based SIF observations at flux tower sites across the mainland China referred as ChinaSpec. Until now, it consists of 15 tower sites including 5 cropland sites, 4 grassland sites, 4 forest sites and 2 wetland sites. At each of these sites, an automated spectroscopy system was deployed to collect continuous super-high resolution spectra for high-frequency SIF retrievals in synergy with EC flux measurements. The goal of ChinaSpec is to provide ground SIF measurements and promote the collaborations between optical remote sensing and EC flux communities in China. We present here the details of instrument specifications, data collection and processing procedures, data sharing and utilization protocols, and future plans. Furthermore, we show the examples how ground SIF observations can be used to track vegetation photosynthesis from diurnal to seasonal scales, to assist in the validation of fluorescence models and satellite SIF products (e.g., from OCO-2, TanSat and TROPOMI) with the measurements from these sites since 2016. This network of SIF observations could improve our understanding of the controls on the biosphere-atmosphere carbon exchange and enable the improvement of carbon flux predictions. This SIF network will also help integrate ground SIF measurements with EC flux networks which will advance ecosystem and carbon cycle researches globally.

We study Sn-to-Lg conversion at regional distances due to significant crustal thickening, particularly in the context of using Sn and Lg amplitude ratios (Sn/Lg) to identify continental mantle earthquakes. We further enhance recent developments in computational seismology to perform 2.5D simulations up to 5 Hz and 2,000 km. Our simulations compare propagation in a reference, constant-thickness crust from a source at three depths straddling the Moho, to 48 models of the same three sources propagating through Moho ramps of four different widths (dips) at four different distances from the source. We compare our synthetics to data from 12 earthquakes recorded on the HiCLIMB array across Tibet, of which six events from northwestern Tibet traverse no major crustal-thickness variation, and six located south of the Himalaya cross a major Moho ramp. Our observations on real data show that amplitude perturbations on individual Sn and Lg waves are smooth and mostly limited to near the ramp end. Even the more-pronounced amplitude variations seen in our simulations show that Sn/Lg for mid-crustal earthquakes is consistently lower than those for mantle earthquakes. Hence we can directly compare Sn/Lg for ramp-crossing and non-ramp-crossing earthquakes and identify new mantle earthquakes in northern India. Sn-to-Lg converted waves may be readily detected near the Moho ramp end through an enhancement in high-frequency content. In addition, we observe higher frequency content in Lg from crustal than from mantle earthquakes, which offers a new discriminant for continental mantle earthquakes based on frequency content of Lg waves alone.

An ENSO event can transition from one event to another in complex ways. An El Niño (La Niña) event can be preceded by a La Niña (El Niño) event to become a cyclic ENSO, by a neutral event to become an episodic ENSO, or by another El Niño (La Niña) event to become a multi-year ENSO. We find that the observed El Niño and La Niña exhibit different complexities in their event-to-event transition patterns. The El Niño is dominated in order by episodic, cyclic, and multi-year transitions, but the reversed order is found in the La Niña. This difference in the transition complexity arises from a subtropical Pacific forcing mechanism that triggers ENSO events. Using observational analyses and forced atmospheric model experiments, we show that a preceding ENSO event can activate a subtropical Pacific forcing mechanism to trigger another ENSO event during the following year. These tropical-subtropical Pacific interactions result in a cyclic ENSO transition if the two ENSO events are of opposite signs or a multi-year ENSO transition if they are of the same sign. The preceding ENSO event should excite deep convections in the tropical Pacific in order to activate the subtropical Pacific mechanism. This requirement enables mean temperatures in the cold tongue and warm pool to respectively control how easily the cyclic and multi-year transitions can occur. This mean state control enables the subtropical Pacific forcing mechanism to result in more multi-year transitions for La Niña than El Niño and more episodic transitions for El Niño than La Niña. Furthermore, a future warmer tropical Pacific is projected to decrease the frequency of occurrence of multi-year ENSO transitions but increase the occurrence of cyclic ENSO transitions.. We find that the CMIP5 and CMIP6 models can reproduce the transition complexity for El Niño but not for La Niña. The models tend to produce too many episodic La Niña events and too few multi-year La Niña events. We are able to link the former deficiency to a weaker than observed subtropical Pacific forcing mechanism in the CMIP5/6 models and the latter to a cold bias in mean state SSTs in the equatorial Pacific in the CMIP5/6 models. To achieve better simulations of ENSO transition complexity, further efforts are to improve the model deficiencies in simulating the SP-onset mechanism and mean SSTs in the equatorial Pacific.

We report the gravity wave (GW) statistics accumulated over two Martian years from the second half of Martian Year 34 (MY34) to the middle of MY36 (May 2018 - February 2022). The observations were performed by the middle- and near-infrared (MIR and NIR, respectively) spectrometers of Atmospheric Chemistry Suite (ACS) on board ExoMars Trace Gas Orbiter (TGO). Temperature profiles obtained independently of both channels during simultaneous measurements show a good agreement, thus providing verification and additional confidence in the data. GW parameters such as temperature fluctuations, potential energy per unit mass, and wave drag are retrieved at altitudes up to 160 km from the MIR channel and up to 100 km from the NIR channel. We present seasonal, intraday and latitude distributions of the wave potential energy and drag, serving to represent the wave activity and impact on the dynamics. A comparison of data obtained during the global dust storm (GDS) of MY34 with the corresponding period of MY35 without a storm reveals a reduction of GW activity in mid-latitudes in agreement with previous observations, and enhancement in the polar regions of both hemispheres, which was predicted by theoretical studies using simulations with a high-resolution circulation model. Seasonal variations of the derived GW activity can be linked to changes in the solar tide.

A document by Kenneth Thorø Martinsen. Click on the document to view its contents.

Most people mainly disadvantaged or lower-middle-income nations reside in the countryside. A resilient community is largely dependent on the physical growth of remote regions. This study aims to assess the catalyst effects of natural hazards like erosion on landscape degradation in rural communities. With a focus on the threat to biodiversity and well-being as it affects the people of Okitipupa, a rural community in Nigeria. To evaluate and handle environmental issues, the Driving Forces-Pressures-State-Impacts-Responses (DPSIR) framework is employed. The socio-economic and socio-cultural factors that propel human activity and either exacerbate or lessen environmental constraints are known as driving forces. A qualitative approach was deployed for this study using a geospatial analysis of the study area within a 1.5x1.5KM sample frame where there is a major gully erosion. The spot heights were taken to generate the soil elevation, the landforms, and the hydrology. There are not many researches that look at how biodiversity or natural resource management techniques and concepts affect mental health in the countryside and rural settlements. There is evidence that extreme weather events or climate have a detrimental effect on mental health, and well-being in rural places. The sustainable landscape design approaches are important due to the heterogeneous and predominant nature of the climate, socio-economy, and landscapes of the rural settlements. This understanding, which addresses the effects on the psychological wellness of the most disadvantaged individuals, can enhance government attempts towards comprehensive management and environmentally conscious preparedness to curb or prevent future reoccurrence.

Mesozoic subduction of the Paleo-Pacific Plate triggered intense tectonism, magmatism, and metallogeny in the eastern South China Block (E-SCB) and set off long-term tectonic, topographic, and climatic responses. However, contrasting hypotheses have been proposed to interpret the timing, style, and evolution of this oceanic subduction. Unraveling the exhumation history of the E-SCB is crucial to understanding deep subduction processes. To address the poorly documented exhumation history of the E-SCB, we present first zircon and apatite (U-Th)/He dates from eight Mesozoic granitoids distributed in a lateral profile across the intracontinental E-SCB. These data are combined with a compilation of regional thermochronological data, in order to address the evolution of the E-SCB in a tectonic, topographic, and climatic evolution framework. Zircon and apatite (U-Th)/He central ages of the investigated plutons range from 146–30 Ma and 82–31 Ma, respectively, implying long-lived exhumation of the intracontinental E-SCB. Inverse thermal modelling indicates the intracontinental SCB underwent multi-phase exhumation events from the Jurassic, despite variable onset timing and the fact that the far intracontinental E-SCB had been an exhumation center prior to the Early Cretaceous. In addition, a compilation map of regional thermochronological data reveals propagation of the exhumation center from the intracontinental to the epicontinental E-SCB over time (from the Cretaceous to the Paleogene). Based on these results, we propose a refined model of Paleo-Pacific Plate subduction since the Triassic. This model is in good agreement with geological observations in the E-SCB and capable of explaining regional magmatism, metallogeny, tectonism, and exhumation.

The tropical temperature in the free troposphere deviates from a theoretical moist-adiabat. The overall deviations are attributed to entrainment of dry surrounding air. The deviations gradually approach zero in the upper troposphere, which we explain with a buoyancy-sorting mechanism: the height to which individual convective parcels rise depends on parcel buoyancy, which is closely tied to the impact of entrainment during ascent. In higher altitudes, the temperature is increasingly controlled by the convective parcels that are warmer and more buoyant, because of weaker entrainment effects. We represent such temperature deviations from moist-adiabats in a clear-sky one-dimensional radiative-convective equilibrium model. Compared with a moist-adiabatic adjustment, having the entrainment-induced temperature deviations leads to higher climate sensitivity. As the impact of entrainment depends on the saturation deficit which increases with warming, our model predicts even more amplified surface warming from entrainment in a warmer climate.

The left-lateral Enriquillo-Plantain Garden Fault (EPGF) is one of two transform systems that define the Northern Caribbean plate boundary zone. Relative motion across its trace (~ 10 mm/yr) evolves from nearly pure strike-slip in western Haiti to transpressional in eastern Haiti, where the fault system may terminate against a south-dipping oblique reverse fault. Lake Azuei is a large (10 km x 25 km) and shallow (< 30 m deep) lake that lies in the direct extension of the EPGF in eastern Haiti. A single core previously collected in the lake suggests high sedimentation rates at its depocenter (~6 mm/yr). The shallow lake stratigraphy is therefore expected to faithfully record any tectonic deformation that occurred within the past few thousand years. In January 2017, we acquired a grid of high-resolution (~10 cm), shallow penetration (~4 to 5 m) subbottom seismic (CHIRP) profiles spaced 1.2 km apart across the entire lake. A new bathymetric map compiled from these CHIRP data and some prior echosounder survey reveals a flat lake floor (<0.01°) surrounded by steep (~5°) shoreline slopes. The CHIRP profiles highlight several gentle folds that protrude from the flat lakebed near the southern shore, an area where transpressional deformation is presumably focused. Thin (< 20 cm) horizontal strata from the lakebed can be traced onto the flanks of these gentle folds and pinch out in an upward curve. They also often pinch upward onto the base of the shoreline slopes, indicating that young sediments on the lakebed bypassed the folds as well as the shoreline slopes. We interpret this feature as diagnostic of sediments deposited by turbidity currents. The fact that young turbidites pinch out in upward curves suggests that the folds are actively growing, and that active contractional structures (folds and/or blind thrust faults) control much of the periphery of the lake. A few sediment cores were strategically located where beds are pinching out in order to maximize stratigraphic records. Two of these cores successfully penetrated strata imaged by the CHIRP profiles. On-going Pb210 dating of sediment samples from the cores should constrain sedimentation rates and thus help quantify the rates of the tectonic deformation.

Coastal aquifers act as a major host of seawater-groundwater interaction and play an important role in modulating the marine elemental budget. Calcium stable isotopes (δ44/40Ca) have been used to identify mass dependent isotope fractionation processes such as carbonate dissolution and precipitation in a range of geological reservoirs that has major implications in constraining global geochemical cycles. However, there is limited Ca isotope data from coastal aquifers globally. Here we report δ44/40Ca values of groundwater collected in 2017-18 from multiple locations and depths from the Bakkhali delta front, Sundarbans, India. The sampling depth varied between 14 m below ground level (m bgl) and 333 m bgl and the salinity of the groundwater samples range from 1-25 ppt. The salinity of the water samples decreases with increasing depth indicating greater seawater incursion from the Bay of Bengal at shallower depths. Variable amounts of mixing of freshwater and seawater is also supported by Sr and Ca concentrations which vary between 1.6-62.8 μmol/l and 0.29-8.92 mmol/l, respectively, and show progressively lower concentrations with depth. The δ44/40Ca values of dissolved phase in groundwater samples (relative to NIST SRM 915a) were measured using a 43Ca-48Ca Double Spike TIMS technique at Centre for Earth Sciences, Indian Institute Science, Bangalore. The δ44/40Ca values of the groundwater samples show significant variability between 1.52-2.28‰ (2SD ~0.1‰) with several samples showing δ44/40Ca values higher than modern seawater (~1.88‰). Low δ44/40Ca values, mostly in deeper groundwater samples, is consistent with higher proportions of freshwater input. Samples showing high δ44/40Ca values are mostly from shallower depths and likely reflect carbonate precipitation which is consistent with high Sr/Ca (~8.13-12.26) in samples from 30-42 m depth. The high δ44/40Ca in groundwater samples from the Ganges-Brahmaputra delta could explain the high δ44/40Ca values reported in water samples from the Bay of Bengal1. [1] Chakrabarti et al., Goldschmidt Boston, 2018 Abstract.

Improved understanding of the impact of crystal mush rheology on the response of magma chambers to magmatic events is critical for better understanding crustal igneous systems with abundant crystals. In this study, we extend an earlier model by (Liao et al, 2018) which considers the mechanical response of a magma chamber with poroelastic crystal mush, by including poroviscoelastic rheology of crystal mush. We find that the coexistence of the two mechanisms of poroelastic diffusion and viscoelastic relaxation causes the magma chamber to react to a magma injection event with more complex time-dependent behaviors. Specifically, we find that the system’s short-term evolution is dominated by the poroelastic diffusion process, while its long-term evolution is dominated by the viscoelastic relaxation process. We identify two post-injection timescales that represent these two stages and examine their relation to the material properties of the system. We find that better constraints on the poroelastic diffusion time are more important for the potential interpretation of surface deformation using the model. We also find that the combination of the two mechanisms causes magma transport to reverse direction in the system, which would successively expose crystals to magma with different chemical compositions.

The Mars Science Laboratory (MSL) Curiosity rover has explored over 400 meters of vertical stratigraphy within Gale crater to date. These fluvio-deltaic, lacustrine, and aeolian strata have been well-documented by Curiosity’s in-situ and remote science instruments, including the Mast Camera (Mastcam) pair of multispectral imagers. Mastcam visible to near-infrared (VNIR) spectra can broadly distinguish between iron phases and oxidation states, and in combination with chemical data from other instruments, Mastcam spectra can help constrain mineralogy, depositional origin, and diagenesis. However, no traverse-scale analysis of Mastcam multispectral data has yet been performed. We compiled a database of Mastcam spectra from >600 multispectral observations and 1 quantified spectral variations across Curiosity’s traverse through Vera Rubin ridge (sols 0-2302). From principal component analysis and an examination of spectral parameters, we identified 9 rock spectral classes and 5 soil spectral classes. Rock classes are dominated by spectral differences attributed to hematite and other oxides (due to variations in grain size, composition, and abundance) and are mostly confined to specific stratigraphic members. Soil classes fall along a mixing line between soil spectra dominated by fine-grained Fe-oxides and those dominated by olivine-bearing sands. By comparing trends in soil vs. rock spectra, we find that locally derived sediments are not significantly contributing to the spectra of soils. Rather, varying contributions of dark, mafic sands from the active Bagnold Dune field is the primary spectral characteristic of soils. These spectral classes and their trends with stratigraphy provide a basis for comparison in Curiosity’s ongoing exploration of Gale crater.

We utilise Principal Component Analysis to identify and quantify the primary electric potential morphologies during geomagnetic storms. Ordering data from the Super Dual Auroral Radar Network (SuperDARN) by geomagnetic storm phase, we are able to discern changes that occur in association with the development of the storm phases. Along with information on the size of the patterns, the first 6 eigenvectors provide over ~80% of the variability in the morphology, providing us with a robust analysis tool to quantify the main changes in the patterns. Studying the first 6 eigenvectors and their eigenvalues with respect to storm phase shows that the primary changes in the morphologies with respect to storm phase are the convection potential enhancing and the dayside throat rotating from pointing towards the early afternoon sector to being more sunward aligned during the main phase of the storm. We find that the ionospheric electric potential increases through the main phase and then decreases after the end of the main phase is reached. The dayside convection throat points towards the afternoon sector before the main phase and then as the potential increases throughout the main phase, the dayside throat rotates towards magnetic noon. Furthermore, we find that a two cell convection pattern is dominant throughout and that the dusk cell is overall stronger than the dawn cell.