Simultaneous pressures of climate change and increasing populations in urban areas have resulted in new stresses on stormwater infrastructure. Altered precipitation patterns require robust and versatile management strategies for stormwater, resulting in increased consideration of greenspace as infrastructure for communities with significant flood risk. There is particular interest in natural, minimally-engineered green infrastructure (GI). Such greenspaces can be heterogeneous and difficult to characterize but are often straightforwardly modelled as black-box systems within a landscape. Many natural sites cannot be approached so simply due to highly permeable interfaces with surrounding landscapes and it is often impossible to monitor the surrounds at anywhere near the same spatial or temporal resolution as within the boundaries of a study site, resulting in uncertainty about the actual benefit of natural greenspace for adjacent communities. We explored water storage in an urban green space, identifying spatio-temporal patterns of internal dynamics to holistically understand site behavior. A dense sensor network in a prairie wetland nature preserve within the Chicago metro area produced 4+ years of high-resolution surface and subsurface water level, soil moisture, precipitation, and air and water temperature data. Responses to weather events in the short term and to climate-driven seasonal effects in the longer term are then described via the combination of GIS methods and signal processing approaches. Power spectral and cross-correlation analyses contribute understanding of relevant timescales for further investigation. Applying hydrograph analysis methods to water level time series yields important statistics about the response of water table elevations throughout the prairie complex, including baseflow elevations and relaxation times. These statistics are used to develop spatial maps of event response as a function of site properties and to identify seasonal effects. Understanding the expected response of stormwater storage in a natural greenspace to a precipitation event has valuable utility for conservation groups and stormwater management utilities. The synthesis of these methods contribute to development of planning tools for siting, design, and management of GI.

Multiyear turbulence measurements from oceanographic moorings in the equatorial Atlantic and Pacific cold tongues reveal similarities in deep cycle turbulence (DCT) beneath the ML and above the core of the Equatorial Undercurrent (EUC). Diurnal composites of turbulence kinetic energy dissipation rate, $\epsilon$, clearly show the diurnal cycles of turbulence beneath the ML in both cold tongues. Despite differences in surface forcing, EUC strength and core depth, DCT persists at all three sites, and is consistent between the sites. Time-mean values of $\epsilon$ at 30 m depth are nearly identical at all three sites. Variations of averaged values of $\epsilon$ in the deep cycle layer below 30 m range to a factor of 10 between sites. A proposed scaling in depth that isolates the deep cycle layers and of $\epsilon$ by the product of wind stress and current shear collapses vertical profiles at all sites to within a factor of 2.

Receiver functions, an important tool in understanding sub-surface interfaces, can be analysed through carefully implemented neural networks. We demonstrate this approach. Previously, we introduced our receiver function tool set, Pythonic Global Lithospheric Imaging using Earthquake Recordings (PyGLImER). PyGLImER enables us to: [1] create a database of teleseismic event displacement records at worldwide seismic stations, [2] compute receiver functions from these records, and [3] compute volumetric common conversion point (CCP) stacks from the receiver functions and their conversion points. CCP stacking is a standard tool to image the subsurface using receiver functions. The CCP stacks represent rich but large, three-dimensional volumes of data that contain information about discontinuities in Earth’s crust and upper mantle. One goal of the interpretation of CCPs is the identification of such discontinuities. Automated picking routines reduce discontinuities to singular peaks and troughs, thus discarding the wealth of information available over the whole depth range, such as integrated discontinuity impedance and regional geometry. However, the obvious alternative, manual picking, is not feasible for large data volumes. Here, we explore the possibility of fully-automated segmentation of 3D CCP volumes through the application of image processing routines and machine learning to successive volume cross-sections. With our picking tool, we manually label discontinuities in CCP slices to serve as training and validation sets.We use these labeled datasets as input to train a convolutional neural network (CNN) to perform pixel-wise identifications in subsurface images. When applied to all slices of the CCP stack, the CNN outputs a fully-segmented 3D model, which furnishes quantitative exploration of subsurface discontinuity morphology. Specifically, we can investigate the thickness/width, intensity, and topography of discontinuities across continents. This information has the potential to improve our understanding of, e.g., mantle transition zone phase transitions and, therefore, mantle dynamics.

For over 30 years, NASA Science Mission Directorate has been a world leader in making the data from its flagship missions available for anyone to use. This data represents a significant public investment and NASA has a mandate to maximize the accessibility of this information for the public good. Along with the data collected by the Missions, NASA has also supported the curation of data that enables ground breaking research in each of our different disciplines. These novel technologies for data access and curation from the different divisions have enabled groundbreaking science. As technology advances and data volumes grow, SMD is working towards even further enhancing the accessibility of the information that NASA produces. This includes new policies to assure that NASA data is FAIR (Findable, Accessible, Interoperable, and Reusable) in the future, leverage techniques and technologies developed by the different divisions for accessing information across the SMD, enabling new technologies like machine learning and cloud processing along with high performance computing, providing support for citation of data through digital object identifiers, creating the ability to search across SMD to enable cross divisional science, and making sure SMD data are accessible to everyone. With these developments, NASA SMD aims to help the community to Transform to Open Science and accelerate the process of scientific discovery. In the process, this will enable SMD science to be even more inclusive, reproducible, and transparent.

The rheological behavior of the lithosphere is examined beneath the Northwestern (NW) Andes (Colombian). Two profiles, one on western and other on eastern of the transition area between the Upper Magdalena Valley (UMV) and the Middle Magdalena Valley (MMV), are obtained from the analysis of the earthquake distribution and the stress drop. Results are consistent with the tectonic and geodynamic context of the western region. In essence, the brittle/ductile transition of the lithospheric crust and mantle is observed, and an approximation of the lithospheric thickness is made. Moreover, the subduction phenomenon of the Nazca Plate under the South American Plate is shown. In the Eastern region, we contemplate an aseismic zone under the Eastern Cordillera below 20 km deep that makes it challenging to know the crust/mantle boundary. This seismic particularity leads us to support the hypothesis of a delamination process due to the tectonic, geological, and thermal context. Our results suggest that the earthquake dataset correlated with rheological estimations may offer a consistent interpretation of the mechanical behavior of the lithosphere.

Sudden stratospheric warmings (SSWs) are impressive fluid dynamical events in which large and rapid temperature increases in the winter polar stratosphere (~0–50km) are associated with a complete reversal of the climatological wintertime westerly winds. SSWs are fundamentally caused by the breaking of planetary-scale waves that propagate upwards from the troposphere. During an SSW, the polar vortex breaks down, accompanied by rapid warming of the polar air column. This rapid warming and descent of the polar air column affects tropospheric weather, shifting jet streams, storm tracks, and the Northern Annular Mode (NAM), including increased frequency of cold air outbreaks over North America and Eurasia. SSWs affect the whole atmosphere above the stratosphere producing widespread effects on atmospheric chemistry, temperatures, winds, neutral (non-ionized) particle and electron densities, and electric fields. These effects span the surface to the thermosphere and across both hemispheres. Given their crucial role in the whole atmosphere, SSWs are also seen as a key process to analyze in climate change studies and subseasonal to seasonal predictions. This work reviews the current knowledge on the most important aspects related to SSWs from the historical background to involved dynamical processes, modelling, chemistry and impact on other atmospheric layers.

Subduction-induced deep hydration and water cycling may play significant roles in the modification and destruction of the overriding cratonic lithosphere. Two contrasting modes are generally proposed: (1) flat subduction (FS) regime with slab subducting sub-horizontally beneath the overriding lithosphere, and (2) big mantle wedge (BMW) regime with slab flattening in the mantle transition zone. Here, systematic petrological-thermomechanical models are conducted to investigate the fluid/melt activities in the contrasting subduction regimes as well as their effects on the modification of overriding lithosphere. The model results indicate that the dehydration process in the FS regime can significantly modify the overriding lithosphere for a region of about 600 km from the trench. During the progressive flat subduction, the partial melting and magmatism migrate towards the inner land of the overriding plate, which will be reversed and backward to the trench during the transition from flat to steep subduction. On the other hand, the deep hydration in the BMW regime is strongly dependent on the sub-crustal serpentinite layer in the subducting slab, whereas the oceanic crust cannot carry water to the transition zone. The modification of the overriding lithosphere in the BMW regime occurs in a larger region of >1000 km from trench, which is however generally slower and weaker. The modification and destruction of North China Craton is more likely to be controlled by the flat subduction of paleo-Pacific plate in the late Jurassic to early Cretaceous, which may be accompanied by the effects of deep water cycling in the BMW regime.

Abu Zarab locality is a part from Um Bogma area in southwestern Sinai, Egypt, where paleokarsts are widespread, especially in carbonate rocks. Abu Zarab area is covered by Carboniferous carbonate rocks containing several paleokarsts. One of these paleokarsts was selected to geochemical investigation. The paleokarst was dissected by three excavated trenches constructed by Nuclear Materials Authority team to reveal its geologic features. The paleokarst is filled with lateritic components represented mainly, by gibbsite, ferruginous siltstone and clay minerals. Twelve samples were collected from the walls of these trenches and chemically analyzed for this purpose in term of major oxides, traces and rare earth elements. The geochemical data of the major oxides display three important geochemical processes in the lateritic components of the paleokarst: (1) Enrichment of aluminum, iron and manganese; (2) depletion of calcium and magnesium (3) silicon experienced both depletion and enrichment. The geochemical data of trace and rare earth elements (REE) display enrichment of U, Cu, Pb, Zn, Ag, As and Cd with obvious enrichment of REE and conversely some elements were depleted such as V, Cr and Ga. It also, noticed that uranium has strong positive correlation with both iron and Aluminum. This paper attempts to establish the relation between uranium and other elements in the paleokarst conditions. It is more likely, according to geochemical features of radioactive elements, that the uranium enrichment process was postdating laterite formation and the iron played an important role in capturing and trapping uranium.

Prior to 2009, the Moon was believed to be anhydrous. However, observations by three spacecraft revealed a hydrated surface by reporting a 3 µm absorption band attributed to hydroxyl and possibly molecular water. The Moon Mineralogy Mapper (M) spectrometer, onboard the Chandrayaan-1 spacecraft is mainly used to study the lunar 3 µm band but its spectral range ends at 3 µm. The limited wavelength range of Mhas allowed observed variations in the 3 µm band to be called into question due to uncertainties in thermal corrections. To investigate the validity of variations in the lunar 3 µm band, we used the SpeX infrared spectrograph at the NASA InfraRed Telescope Facility at Maunakea Observatory in Hawaiʻi. With SpeX, we are able to obtain lunar data over a wavelength range of 1.67 to 4.2 µm at 1 – 2 km spatial resolution. The long wavelengths provide strong constraints on thermal emission corrections. We confirm that the 3 µm band varies with lunar time of day as well as with latitude and composition. Each observation reveals strong variations in abundances of hydroxyl and possibly molecular water. The data reveal a decrease in abundance with increasing lunar local time, an asymmetric trend about the equator that favors the southern latitudes, and higher concentrations in highland regions. The longer wavelengths provided by SpeX have allowed us to examine variations in the 3 µm band and provide definitive evidence that the variations are due to changes in hydration.

This paper describes laboratory experiments (using a high-speed wind-wave flume) of the effects of water waves on heat and momentum exchange in the near-water atmospheric boundary layer at high wind speeds. Different from previous experiments of this type, the parameters of waves were controlled by a net stretched along the entire channel to effectively decrease the fetch. This helped to achieve dependency of the transfer coefficients on two independent parameters, namely the wind speed and fetch. Another key to the experiment was using a stable temperature stratification of the air flow, with the temperature of the air entering the flume 15–25 degrees higher than the water. The experiments showed a sharp increase in the heat exchange coefficient at winds exceeding 33–35 m/s, similar to that observed earlier in the high-speed wind-wave flume of Kyoto University with conditions of unstable temperature stratification of the air flow. The joint analysis of the data obtained in the high-speed wind-wave flumes of IAP RAS and Kyoto University yields the universal dependency of the exchange coefficients and the temperature roughness on the peak wave number of surface wave spectra. This is independent of the type of temperature stratification of the atmospheric boundary layer, either stable or unstable. The sharp increase in the heat exchange coefficient is shown to be associated with increased whitecapping.

Many exposed high-pressure meta-serpentinites comprise a channelized network of olivine-rich veins which formed during dehydration at depth and served as pathway for fluid escape. Previous studies showed that the formation of an olivine enriched vein-like interconnected porosity network on the µm-scale is controlled by chemical heterogeneities in the rock. However, the evolution towards larger scale and nearly pure olivine veins is not yet well understood. Here we study the effects of reactive fluid flow on a developing vein system during dehydration. We use thermodynamic equilibrium calculations to investigate the effects of bulk silica content variations in serpentinites on the dehydration reaction of antigorite + brucite = olivine + free fluid and silica content of this fluid phase. We develop a numerical model combining the effects of intrinsic chemical heterogeneities with reactive silica transport. Increasing temperatures lead to local fluid overpressure and the liberation of a silica-poor fluid in a subdomain with initially increased bulk iron and decreased silica content. The fluid overpressure drives fluid flow into other subdomains where the fluid enhances dehydration and leads to olivine enrichment in an iron-enriched vein. Our model shows how reactive silica transport can lead to vein widening and olivine enrichment within the veins as observed in the Erro Tobbio meta-serpentinites. Thus, reactive fluid flow is a critical step in the evolution towards a larger scale vein system and a dynamic porosity evolution by accounting for a chemical feedback between the dehydrating rock and the liberated fluid.

To determine the times of travel within a 170.6 km long reach in the upper Yellow River, we carried out a dye experiment in May 2017. 48.75 kg of dye was poured simultaneously at 39 points on a floating bridge. Water samples at eight sites were collected at left bank flow, center flow, and right bank flow considering both the traffic convenience and the safety production. A Fluorometer 10-005 was used to measure the dye concentration in the water samples. A three-parameter lognormal distribution equation, where the logarithm is to the base e, was used to fit the observed time concentration data to establish the time-concentration response curve and to establish the probability density function. For a conservative tracer, the time concentration curve was generated by multiplying the fitted probability density function and its coefficient. The travel times of different parts of the dye plume for the seven sampling sites and mean velocities and longitudinal dispersion rates for five sub reaches were calculated. The mean velocities of centroid of dye plume ranged from 0.49 m $s^{-1}$ to 0.69 m $s^{-1}$ and the dispersion rates range from 0.13 m $s^{-1}$ to 0.37 m $s^{-1}$ for the discharge of 233 $m^3$ $s^{-1}$ measured at the Baotou hydrometric station. Several empirical relations are given for attenuation of the peak probability density, passage time, travel times of leading-edge, travel times of centroid and travel times of trailing edge of the dye plume in the upper Yellow River, Baotou, Inner Mongolia, China.\\

Forests exchange CO and O with the atmosphere at similar molar ratios. Correspondingly, the apparent respiratory quotient (CO/O flux ratio, ARQ) is expected to be ≈1 given the stoichiometry of organic substrates in soils and plants. However, measured ARQ values often deviate from ≈1, and it is still unclear how CO and O fluxes are balanced among ecosystem components, and what are the sources of ARQ variability. Here we measured ARQ of soil pore space air (ARQ), and in headspace air from incubations of bulk-soil (ARQ), tree stem-cores (ARQ) and roots in 10 measurement campaigns over 15 months in a Mediterranean oak forest. Mean (range) values were: ARQ = 0.76 (0.60-0.92), ARQ = 0.75 (0.53-0.90), and ARQ = 0.39 (0.19-0.70). As expected, ARQ was usually higher than ARQ and lower than the ARQ of incubated roots (range of 0.73-0.96). Variability in ARQ was correlated with soil moisture parameters. Temperature positively correlated with ARQ and ARQoutside the growing season. Abiotic O uptake by Fe was demonstrated to reduce ARQ, but this effect would be significant under field conditions only if respiration rates are very low. We hypothesize that low measured ARQ values likely result from selective decomposition of reduced compounds and physical protection of oxidized compounds. ARQ, measured at two stem positions, was lower than expected from oxidation of any possible substrate, indicating partial retention of respired C. The overall ARQ <1 reveals an imbalance of stem-soil CO and O fluxes that is unexpected at the ecosystem level.

This article objectively estimates the spatiotemporal evolution of b values before and after two large earthquakes during 2000-2019 along the Longmenshan fault. We apply the Akaike information criterion to statistically assess the temporal variation in b values and use the b value time series behavior as a tool to quantify the effect of a mainshock on the size distribution of aftershocks. The b values in the source regions exhibited decreasing trends prior to two large earthquakes on 12 May 2008 ( 8.0) and 20 April 2013 ( 7.0). Moreover, the times required for the b values to return to a stable state after both mainshocks were basically equivalent to the times taken for aftershocks depth images to cease to change visibly (approximately 1 year following the 8.0 event and approximately 10 months following the 7.0 event). Our results have substantial implications for assessing the hazards of aftershock sequences.

Detecting a seismic event from Europa’s silicate interior would provide information about the geologic and tectonic setting of the moon’s rocky interior. Reflections off a metallic core would indicate the presence, size, and state of the hypothesized core. However, the subsurface ocean will attenuate the signal, possibly preventing the waveforms from being detected by a surface seismometer. Here, we investigate the minimum magnitude of a detectable event originating from Europa’s silicate interior. We analyze likely signal-to-noise ratios and compare the predicted signal strengths to current instrument sensitivities. We show that a magnitude M_w >3.5 would be sufficient to overcome the predicted background noise. However, a minimum magnitude of M_w > 5.5 would be required for current instrumentation to be able detect the event. A thinner ice shell transmits greater ground acceleration amplitudes than a thicker ice shell, which might allow for M_w > 4.5 to be detectable.

Vegetation is a natural component of river systems and plays important hydrological, ecological and geomorphic roles. However, vegetation cover and dynamics are controlled by numerous factors operating at multiple scales, making it challenging to determine the drivers of changes over time. The Beas and Sutlej Rivers are two of the ‘water towers’ of the Himalayas that supply water and power for large populations. Previous research has shown that significant geomorphic change has occurred over that last 150 years in both rivers, with differences in the type and magnitude of change in the last few decades. The aim of this study was to quantify the spatial distribution and dynamics of riparian and in-channel vegetation in two Himalayan rivers and evaluate the local and global drivers, such as climate change, alteration of river flows, and river geomorphic adjustment. Annual changes in vegetation cover and channel width were quantified using Normalized Difference Vegetation Index (NDVI), modified Normalized Difference Water Index (mNDWI), and a multispectral supervised classification over a 30-year period, for pre- and post-monsoon seasons, using Landsat data. The results show statistically significant upward trends in NDVI across both catchments, indicating large-scale drivers of change. Relatively greater increases in NDVI in the valley bottom and the active channel zones suggest more localized processes such as recruitment and succession of vegetation and conversion to agriculture following channel narrowing. Spatial variations in vegetation dynamics helps us to better understand vegetation-geomorphology interactions in these large systems and the impacts of human activity and climate change.

Living shorelines are native marsh plantings that control coastal erosion and provide coastal resilience to sea level rise (SLR) by migrating upland during SLR. Living shorelines require ripraps to dissipate wave energy which prevent marsh boundary erosion and facilitate sedimentation. Currently, ripraps are built with rocks which cannot adapt to SLR to continue attenuating wave energy. Alternatively, oyster castles are modular cinder blocks for building breakwaters and coastal structures that initiate the development of oyster reefs which can grow equivalently with SLR. Thus, oyster castle breakwaters can adapt to SLR while retaining their breakwater function. This research used Delft3D and SWAN to model the effects of climate changes, especially SLR, on coastal morphology with 3 domain configurations: 1) only marsh, 2) traditional living shoreline with riprap and 3) living shoreline with oyster castle. We built a model comparing marsh deposition between these coastal structures over time, and determined the most important parameters affecting living shoreline evolution. All domains were 2 km wide by 1 km in length to mimic coastal bay conditions. Model runs were set up for a temporal scale of 150 days. This duration was increased by a morphological factor of 150 to project our results to 30 and 60 years. The parameters tested included vegetation density, nearshore slope, SLR, and suspended sediment concentration (SSC). Oyster castles facilitated greater marsh deposition than riprap at +8.9 mm under current sea level, +3.5 mm with SLR of 0.4 m, and +3.3 mm with SLR of 0.8 m. Increased nearshore slope and higher SSC both increased sediment deposition in the marsh. Increased sea level and higher marsh density decreased maximum bed shear stress. Therefore, coastal restoration efforts should strive to integrate oyster castle into living shorelines, and increase marsh density to enhance sediment deposition and coastal resilience. Our modelling efforts focus on quantifying the impacts of coastal processes on created marsh dynamics.

River deltas and enclosed lagoons represent a zone where fluvial and littoral processes interacts through a redistribution, erosion, and deposition of sediment, with a huge impact on coastal management and engineering. The focus of the study is to understand the correct balance between strategies to maintain the navigational efficiency of tidal inlets and the respect of the ecological and economical function in coastal lagoons. We applied an integrated modeling system which will link multiple hydrodynamic and morphodynamic models to understand how coastal processes and the associated sediment transport can influence the functioning of the southern inlet of the Barbamarco lagoon in the Po River Delta, Italy. Furthermore, our study provides engineering solutions aimed at the inlet functioning efficiency with a proposal for the monitoring plan. Our results highlight the importance of the seasonal effects of wave climate on the littoral sediment transport. Model outcomes show that the dredging volume is approximately 15,000 cubic meter/year for the southern inlet that might vary with wave climate. However, shaping a wider tidal channel seaward will reduce the dredging activities with a longer interval than the actual sediment removal. A design of a deeper and wider channel will deflect the along shore current seaward with a sediment bypass of the inlet. Therefore, the sediment will reach the erosional side of the inlet enhancing the redistribution of the sediment which might reduce the over-wash during storms and high-water levels. Our results display the ephemeral equilibrium of tidal inlets and coastal lagoons in deltaic systems impacted by large riverine sediment delivery. Shore management scenario and decision relies on hydro-morphodyanmic numerical model to predict the best practice for coastal sustainability.