The Sudan-Sahel region has long been vulnerable to environmental change. However, the intensification of global warming has led to unprecedented challenges that require a detailed understanding of climate change for this region. This study analyzes the impacts of climate change for Burkina Faso using eleven climate indices that are highly relevant to Sudan-Sahelian societies. The full ensemble of statistically downscaled NEX-GDDP-CMIP6 models (25 km) is used to determine the projected changes for the near (2031-2060) and far future (2071-2100) compared to the reference period (1985-2014) for different SSPs. Validation of the climate models against state-of-the-art reference data (CHIRPS and ERA5) shows reasonable performance for the main climate variables with some biases. Under the SSP5-8.5, Burkina Faso is projected to experience a substantial temperature increase of more than 4.3°C by the end of the century. Rainfall amount is projected to increase by 30% under the SSP5-8.5, with the rainy season starting earlier and lasting longer. This could increase water availability for rainfed agriculture but is offset by a 20% increase in evapotranspiration. The country could be at increased risk of flooding and heavy rainfall in all SSPs and future periods. Due to the pronounced temperature increase, heat stress, discomfort, and cooling degree days are expected to strongly increase under the SSP8.5 scenarios, especially in the western and northern parts. Under the SSP1-2.6 and SSP5-8.5, the projected changes are much lower for the country. Thus, timely implementation of climate change mitigation measures can significantly reduce climate change impacts for this vulnerable region.

Most state-of-the-art deep learning systems have their roots in computer vision, which force the remote sensing community to develop ad-hoc procedures for applying deep learning methods in the analysis of remote sensing data. In this Juypuiter notebook, we present Keras Spatial (https://pypi.org/project/keras-spatial), a new python package for pre-processing and augmenting geospatial data for deep learning models. Keras Spatial is composed of loosely-coupled components, which allow users to pre-process geospatial raster data on-the-fly before ingesting them into neural networks. The advantage of using Keras Spatial over more traditional Ad-hoc pipelines are (1) allowing scientists and developers to work in projected coordinates rather than pixels and (2) controlling the sample space and hence avoiding issues such as bias and class imbalance during training. We will demonstrate Keras Spatial using the case study of processing digital elevation data for a segmentation model. We will also demonstrate advanced data pre-processing features of this package, such as accessing remote data sources directly, easy integration of multiple datasets using automatic reprojection and resampling, and decoupling training samples dimensions from the geographic extent to open the door for prediction across different scales.

This study compares the impacts of global warming and intense anthropogenic heat (AH) on extreme hourly precipitation over the Pearl River Delta (PRD) megacity, located in coastal South China. Using the cloud-resolving Weather Research and Forecasting (WRF) model coupled with the single-layer urban canopy model (SLUCM), three downscaling experiments were carried out: the first (second) having zero (300W/m2 as diurnal maximum) AH values prescribed over PRD urban grids, under the same current climate conditions. The third experiment with AH=300W/m2 under future projected climate representative concentration pathway (RCP) 8.5. Boundary conditions were derived from PRD extreme rainfall episodes, identified from the Geophysical Fluid Dynamics Laboratory Earth System Model (GFDL-ESM2M) historical and RCP8.5 runs. Global warming forcing leads to ~20 to more than 100% increase in the probability of hourly precipitation with the magnitude of 20-100mm/hr over urban locations. The enhancements from intense AH forcing were similar. However, two types of forcings have distinct signatures in modulating the thermodynamic environment. Warming due to AH is limited to the lowest 1km above ground, while global warming warms up the whole troposphere. Intense AH results in enhanced convective available potential energy (CAPE) and reduced convective inhibition (CIN) within the megacity, allowing convection to be triggered more easily and with more vigor. On the other hand, global warming enhances both CAPE and CIN, over both urban and rural areas. Our results highlight the different physical mechanisms of AH and global warming in exacerbating extreme urban rainfall, despite their having similar impacts on the rainfall intensity.

As we approach 2020, there are more well bores that require abandonment than well bores waiting to be drilled. The USA alone has ~1.7 Million well bores with an API number indicating that they are not permanently plugged, therefore will be in need of Plugging and Abandonment (P&A) at some point in the future. Some of these well bores are located in fragile ecosystems, such as the Gulf of Mexico, where it is estimated that 9,000 idle well bores are waiting permanent plugging and abandonment. The numbers of future P&As suggest requirement for an urgent improvement of current technology as many governments are preparing standards that require assurance for zero leakage over thousands of years. This paper/talk will present knowledge gaps we identified during literature review and the data obtained during first two terms of the ongoing project , under NASEM-GRP funding. Extensive literature review points to the following issues: 1) Portland-cement based materials, with their pH ~13, are geochemically incompatible with the reservoir conditions in the GoM. 2) Weak interfaces between and contamination with drilling fluids in well bore structures present high risk for Hydrocarbon leakage, which currently cannot be mitigated successfully. Placement and accessibility of well bore in offshore environment adds to technological complexity and increases the risk of leakage. 3) Monitoring and verification is currently not available for long-term assessment offshore. Some of our preliminary data suggests the following: 1) Plugging materials are impacted by contamination form drilling fluids and other well bore materials, such as fragment of dehydrated clays, oily rock fragments. 2) Casing corrosion might lead to deterioration of primary well bore cement, which can be difficult to locate and re mediate prior to plugging. 3) Geo-mimicry is a potential path forward in designing and developing barrier materials capable of serving over thousands of years.

Earth's upper mantle rheology controls lithosphere-asthenosphere coupling and thus surface tectonics. Rock deformation experiments and seismic anisotropy measurements indicate that composite rheology (co-existing diffusion and dislocation creep) occurs in the Earth’s uppermost mantle, potentially affecting convection and surface tectonics. Here, we investigate how the spatio-temporal distribution of dislocation creep in an otherwise diffusion-creep-controlled mantle impacts the planform of convection and the planetary tectonic regime as a function of the lithospheric yield strength in numerical models of mantle convection self-generating plate-like tectonics. The low upper-mantle viscosities caused by zones of substantial dislocation creep produce contrasting effects on surface dynamics. For strong lithosphere (yield strength >35 MPa), the large lithosphere-asthenosphere viscosity contrasts promote stagnant-lid convection. In contrast, the increase of upper mantle convective vigor enhances plate mobility for lithospheric strength <35 MPa. For the here-used model assumptions, composite rheology does not facilitate the onset of plate-like behavior at large lithospheric strength.

Wind erosion is integral to the evolution of arid landscapes on Earth and Mars, but the nature of long-term wind erosion of bedrock is poorly understood. Here we describe the Salina del Fraile (SdF) depression in the Puna Plateau of the Central Andes, NW Argentina, as a landform excavated by wind over several million years. New structural cross-sections and a compilation of chronostratigraphic ages rule out the hypothesis that the depression was created by transtensional tectonics. Dated remnant lacustrine and alluvial deposits in the floor of the depression constrain the rate and timing of erosion. Late Oligocene–Miocene compressional folding uplifted friable strata that were preferentially eroded, resulting in the high-relief (900 m) depression. Up to 1.95 km and an average of 1.05 km of strata were eroded during the last 8.2 to 17 Ma, at rates of 0.06 to 0.23 mm/yr. These rates are similar to long-term average wind erosion rates reported in other regions. Coarse-grained eolian megaripples, yardangs, and elongated ridges indicate ongoing eolian abrasion and deflation, aided by salt weathering, of the floor of the depression. Megaripple migration across stony lag surfaces exposes fresh bedrock to continued erosion. The SdF also contains kilometerscale mesas and ridges that we interpret as erosional remnants. These landforms are similar to megayardangs and erosional topography identified on the lower flanks of Mount Sharp, Gale crater, Mars. In such hyperarid landscapes characterized by lithologic heterogeneities, high relief landforms can be generated and sustained by wind erosion, without significant fluvial or glacial incision.

Submarine slope failures and the tsunamis they generate pose risks to coastal communities and infrastructure. While slope failures on passive margins represent some of the largest mass failures on Earth, little is known about their dynamics. The recurrence interval of submarine slope failures on passive margins is longer than on active margins, which facilitates thick sediment accumulation before failure, yields larger failures, and may be associated with higher potential for tsunami generation. While numerous studies model failure likelihood based on temporal distribution, overpressure, or earthquake proximity, there is limited insight linking initial conditions, preconditioning, slope failure initiation, and failure evolution. We observed dynamic submarine slope failure processes via physical experiments in a benchtop flume. Submarine slope failures were induced under controlled pore pressure with varied sand-clay mixtures (0%, 2%, 4%, and 5%, clay, by weight) constrained to a constant pre-failure slope geometry. Commercially obtained fine-grained sand (subangular quartz; 87% SiO2; D50 = 195 µm) and clay (dioctahedral smectite; 63% SiO2 and 21% Al2O3; D90 = 44 µm) were used. Pore pressure required to induce slope failure, slope-failure initiation and evolution, and post-failure morphology were recorded and analysed via photogrammetry. Numerical models were developed to quantify the physical processes observed in flume experiments. Increased clay content corresponded to increased cohesion and pore pressure required for failure. Subsurface fractures and tensile cracks were only generated in experiments containing clay. Falling head tests showed a log-linear relation between hydraulic conductivity and clay content which we used in our numerical models. Models of our experiments effectively simulate overpressure (pressure in excess of hydrostatic) and failure potential for (non)cohesive sediment mixtures. Overall our work shows the importance of clay in reducing permeability and increasing cohesion to create different failure modes due to overpressure. Ongoing work is investigating the effects of higher clay content and the role of seismic energy in slope failure morphology.

Recently, Uchida et al. [2016, Science] revealed the periodic changes in the interplate locking in the northeast Japan subduction zone based on the activity of small repeating earthquakes and terrestrial crustal deformation data. They found that slow slip on the plate interface has occurred repeatedly at intervals of from 2 to 6 years, depending on the location. In the northern part of the Japan Trench, a tsunami earthquake occurred with rupturing the shallow plate boundary in 1896, but it is not well understood whether the coseismic slip fully released the interseismic slip deficit, and whether periodic slow slip events occur near the trench or not. In order to investigate the interplate locking state in this region, we have just started a research project titled “Head and tail of massive earthquakes: Mechanism arresting growth of interplate earthquakes” (JSPS KAKENHI Grant Number JP19H05596), under which GNSS-Acoustic observation to detect the seafloor crustal deformation will be performed more frequently than ever before. To accomplish frequent observations, we have been developing automatic GNSS-A data acquisition system using an unmanned surface vehicle, the Wave Glider. As a first observation, we have performed GNSS-A observation at a seafloor station off Aomori Prefecture in this July. The Wave Glider (SV3-240) was equipped with 2 GNSS antennas, acoustic transducer, MEMS gyro, and their control and logging units. The data acquisition from these sensors and the autonomous activation of the seafloor transponders were successfully executed only with turning the power supply to the payload on/off from land via a satellite communication. The Wave Glider rarely strayed off the configured course, and the solar panels generated enough power to perform the observations although the weather was mostly cloudy during the operation. Now, we are processing the obtained data, and the results will be presented at the meeting.

Since mid-2008, automated radio monitoring networks such as the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) have been observing and logging global amateur radio high frequency (HF, 3-30 MHz) communications. These networks are built and operated by amateur radio operators for amateur radio purposes, but the data are also useful for the study of ionospheric space weather and ionospheric science. Ham Radio Science Citizen Investigation (HamSCI) members will present global observations of over 1.9 billion radio reports on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands. The observations span an 11-year period from 2009-2020. We find a correlation between HF propagation path characteristics and the solar EUV output through the F10.7 index, along with solar cycle effects, seasonal effects, and sporadic E signatures. We will also discuss impacts of operator behavior and sampling effects caused by the distribution of amateur radio transmitting and receiving stations.

Representation of canopy and tree function in earth system models (ESMs) is going through rapid advancements in the last decade. The simplistic big-leaf representation of canopy in model is being expanded and replaced by more complex canopy representations that include multiple functional types, species and age/size stages, multiple patches with different canopy height and leaf area characteristics, and vertically detailed representations with between 2 (light and shade) to n canopy leaf layers. Recently, the hydrodynamic approach to modeling stomata conductance has advanced, and many ESMs include a hydrodynamic version. Under the hydrodynamic approach, stomata respond to water availability in the xylem, and not directly in the soil. The result is a model that include the stem, and xylem dimensions as canopy characteristics for determining the flow and storage of water in the xylem. However, pipe diameter, area and volume do not scale linearly, and thus, the simulations cannot resolve canopy-scale hydrodynamics by pulling all the stem conductive area and volume to a single virtual patch scale, but instead, need to consider the hydrodynamics of a single virtual tree and scale its resulting fluxes to the entire canopy. While that is trivial in a homogeneous canopy, the difference between the tree-level description of the hydrodynamic canopy and the horizontally pulled description of the canopy in the surface-flux and radiation-exchange modules leads to a conundrum. Imagine a mixed canopy: 50% oaks and 50% maples. Assume oaks have 20% more LAI and are 1 m taller than the maples. As far as hydrodynamics are concerned, the evaporative demands of maple follow from light attenuation and leaf area profiles of a maple-like canopy. However the roughness length and aerodynamic resistance, and the resulting wind profile inside the canopy is not characteristic of maple or oak but is a result of the mixed canopy. I will present formulation for a consistent scaling of tree-level canopies to patch-level for mixed forests with multiple species of different functional types. The formulation scales canopy characteristics and the resulting canopy fluxes from tree to forest in an energy and mass-conservative way, and allow a smooth and consistent multi-species canopy description for hydrodynamic models in mixed-forests.

In Arctic winter and spring 2020, the stratospheric temperatures were exceptionally low for a long time period and the polar vortex was very stable. As a consequence, significant ozone depletion occurred in Northern polar regions in spring 2020. Here, we present simulations by the Chemical Lagrangian Model of the Stratosphere (CLaMS) that addresses the development of chlorine compounds and ozone in the polar stratosphere in 2020. The simulation is able to reproduce relevant observations which is shown by comparisons with MLS, ACE-FTS and OMI data. Although the concentration of chlorine and bromine compounds in the polar stratosphere has decreased by more than 10% compared to the peak values around the year 2000, the meteorological conditions in winter and spring 2020 caused an unprecedented ozone depletion. The simulated lowest ozone mixing ratio was around 0.05 ppmv and the ozone depletion in the vortex core in the lower stratosphere reached 133 Dobson Units, which is more than the loss in the years 2011 and 2016 that had the largest Arctic ozone depletion so far.

Quantifying interseismic deformation of fault networks which are predominantly deforming in a north-south direction is challenging, because GNSS networks are usually not dense enough to resolve deformation at the level of individual faults. The alternative, synthetic aperture radar interferometry (InSAR), provides high spatial resolution but is limited by a low sensitivity to N-S motion. We study the active normal fault network of Western Anatolia, which is undergoing rapid N-S extension, using InSAR. In the first part of this study, we develop a workflow to assess the potential of decomposing InSAR line-of-sight (LOS) velocities to determine the N-S component. We use synthetic tests to quantify the impact of noise and other velocity components and outline the requirements to detect N-S deformation in future studies. In its current state, the N-S deformation field is too noisy to allow robust interpretations, hence in the second part we complement the study by including vertical deformation. Since most faults in the study region are normal faults, the high-resolution vertical velocity field provides new insights into regional active faulting. We show that tectonic deformation in the large graben systems is not restricted to the main faults, and seemingly less active or inactive faults could be accommodating strain. We also observe a potential correlation between recent seismicity and active surface deformation. Furthermore, we find that active fault splays causing significant surface deformation can form several kilometres away from the mapped fault trace, and provide an estimate of current activity for many faults in the region.

Episodic Tremor and Slip, or ETS, occurs frequently in Cascadia with recurrence intervals of roughly 8-22 months for large ETS. Characterizing these events is critical to our understanding of subduction plate interface mechanics, plate motion budgets, and the potential for damaging earthquakes. Here we combine a novel technique for separating ETS and inter-ETS velocities with the Network Inversion Filter [Segall and Matthews,1997; McGuire and Segall, 2003; Miyazaki et al., 2006] to fully characterize ETS slip using daily GPS time series. The velocity separation technique allows for an inversion of the stacked, time-averaged ETS velocities to obtain a time-averaged ETS slip rate on the plate interface for the last 10-20 year time period. These time-averaged velocities are directly comparable to plate rate to characterize the overall slip budget. We use time dependent NIF inversions with our newly derived inter-ETS velocities to create a catalog of ETS events. Slip and tremor track closely in all ETS events, consistent with prior results [Bartlow et al., 2011; Wech and Bartlow, 2014]. We generate heterogenous elastic Green’s functions for both of our inversions using the PyLith finite element code [Aagaard et al., 2013], based on the velocity model of Stephenson [2007] to better estimate slip amplitudes. We find that while 75-100% of the plate rate is accommodated in the northern segment, consistent with prior results [Chapman and Melbourne, 2009], in the central segment and parts of the southern segment ETS accommodates only 0-50% of the plate rate, leaving additional slip to be released as inter-ETS creep, in an earthquake, as posteseismic relaxation, or as ETS slip at other points in the megathrust earthquake cycle. Currently published locking models [Schmalzle et al., 2014; Pollitz and Evans, 2017] indicate that inter-ETS creep is likely to take up most of the remaining slip budget, but some coupling may remain in the ETS zone.

Scalar parameters of various aspects of magnetic reconnection offer easily comparable measures of the characteristics of the diffusion regions surrounding X-lines in a way arguably more general than other attributes which may depend on the coordinate system used. We performed a principal component analysis (PCA) of several scalar parameters including measures of relative magnetic field line (MFL) curvature, ion agyrotropy, energy conversion rate, electric field, and current density in the time spans surrounding and including independently identified ion diffusion regions (IDRs) observed by MMS in the geomagnetic tail. We find that relative MFL curvature is the most bold indicator of an IDR encounter while some more traditional measures vary comparatively little between IDRs and the regions adjacent to them when averaged across events. More granular statistics are also presented and discussed.

Climate projections suggest that snowfall-dominated areas will decline substantially in the coming decades. Such climate impacts are already being observed in Colorado where the dominant source of annual peak discharge is shifting from snowmelt to rainfall, altering the paths by which water flows through a landscape and is ultimately delivered to streams. Observed climate driven shifts in stream flow dynamics and permanence highlight the increasing importance of understanding the hydrologic connectivity of uplands to streams in lower elevation, montane ecoregions. We collected geochemical and hydrometric data over three years to quantify hydrologic connectivity of uplands to a montane headwater stream at the Manitou Experimental Forest in central Colorado. We use a combined approach of concentration-discharge relationships and end-member mixing analysis, paired with high resolution measurements of soil moisture, precipitation, and groundwater levels to characterize source areas to the stream in 3-dimensions: longitudinal, lateral, and vertical. Samples were collected and measurements were recorded along the stream profile (longitudinal), from groundwater wells and soil lysimeters installed with increasing distance from the stream (lateral), and from shallow versus deep groundwater wells and soil moisture measured at different depths (vertical). Results indicate distinct differences in stream chemistry along the longitudinal stream profile, with highest concentrations at the most upstream sites and lowest concentrations at the most downstream sites. Stream solute concentrations increased with decreasing stream discharge values from spring to late summer. However, the stream remained chemostatic during all recorded rain storms, suggesting a difference in flow pathways during individual summer storm pulses. End member mixing analysis suggests spatiotemporal differences in shallow and deep vertical source areas, and between riparian and upland sources to the stream. These results provide a promising step towards quantifying the expansion and contraction of runoff source areas to a montane headwater stream.

The boundary between the overriding and subducting plates is locked along some portions of the Cascadia subduction zone. The extent and location of locking affects the potential size and frequency of great earthquakes in the region. Because much of the boundary is offshore, measurements on land are incapable of completely defining a locked zone in the up-dip region. Deformation models indicate that a record of seafloor height changes on the accretionary prism can reveal the extent of locking. To detect such changes, we have initiated a series of calibrated pressure measurements using an absolute self-calibrating pressure recorder (ASCPR). A piston-gauge calibrator under careful metrological considerations produces an absolutely known reference pressure to correct seafloor pressure observations to an absolute value. We report an accuracy of about 25 ppm of the water depth, or 0.02 kPa (0.2 cm equivalent) at 100 m to 0.8 kPa (8 cm equivalent) at 3,000 m. These campaign survey-style absolute pressure measurements on seven offshore benchmarks in a line extending 100 km westward from Newport, Oregon from 2014 to 2017 establish a long-term, sensor-independent time series that can, over decades, reveal the extent of vertical deformation and thus the extent of plate locking and place initial limits on rates of subsidence or uplift. Continued surveys spanning years could serve as calibration values for co-located or nearby continuous pressure records and provide useful information on possible crustal deformation rates, while epoch measurements spanning decades would provide further limits and additional insights on deformation.

Hydro climate services, such as early warning systems and monitoring and forecasting services for floods and droughts, are required to deal with climate risk management and adaptation. Those tools also contribute to achieving international goals and commitments such as Sustainable Development Goals (SDGs), the Paris Agreement and the Sendai Framework for Disaster Risk Reductions. Recognizing these needs, UNESCO’s International Hydrological Programme (IHP) has fostered the creation and application of many such products in recent years. This has been accomplished through unique formal and informal partnerships among IHP programs, such as the Global Network on Water and Development Information for Arid Lands (G-WADI) and the International Flood Initiative (IFI); UNESCO regional and country offices in Africa, Latin America and Asia; university engineering and hydrology departments; and UNESCO’s network of affiliated (“category 2”) centers, such as the International Center for Integrated Water Resources Management (ICIWaRM) and the International Centre for Water Hazard and Risk Management (ICHARM). The presentation will include an overview of the products, tools and services developed through these collaborations among IHP and its “water family” and their effectiveness in providing such services to Member States.

We detected shallow very low frequency earthquakes (VLFEs) off the Cape Muroto and Kii Channel in the Nankai subduction zone and estimated their moment rate functions. Combining the new and previously estimated catalogs, we obtained the comprehensive catalog of shallow VLFE moment rate functions along the Nankai Trough. We defined the shallow VLFE swarms and investigated the scaling relationships of their cumulative moments, activity area, and durations in each region. Detected swarms were considered candidates for shallow slow slip events. A similar scaling relationship was observed between the cumulative moments and activity areas, irrespective of regions. It indicates similar stress drops in each region. However, the relationship between the cumulative moments and durations varied. This difference was explained by the along-strike variations in the faulting conditions of shallow slow earthquakes, such as material or hydrological properties.