Brazil is one of the richest countries in water resources and is currently the second largest global supplier of food and agricultural products. Furthermore, more than 70% of Brazilian energy comes from hydropower. Therefore, to ensure water availability for future generations it is necessary to consider the Nexus thinking (water, food, energy, ecosystem service, and social aspects integrated) in the country. However, few studies have been developed considering the Nexus thinking in Brazil. Understanding the interconnected risks and vulnerability to these sectors under climatic change conditions is crucial for the development of sustainable resources management plans and for mitigating competition among them. Here, we assess the Food-Energy-Water Nexus considering climate and land cover and land use changes (LCLUC) scenarios in the São Francisco river basin. This basin is the third largest basin in Brazil and supplies water to approximately 14 million inhabitants, with the Metropolitan Region of Belo Horizonte being the most populous area. The São Francisco river has been used for water supply, irrigation, agriculture and transportation by waterways, but its preponderant use is for hydroelectric power generation. However, this basin has been suffering from LCLUC and drought that has plagued the region since 2012. In addition, part of the river flow has been diverted due to the transposition of the São Francisco river to supply water to the semi-arid region of Brazil. We will calibrate and evaluate the Soil and Water Assessment Tool (SWAT) using hydrometeorological data from 1972 to 2017. We will also use LCLUC scenarios from the OTIMIZAGRO model and regional climate change models (HadGEM2-ES and MIROC5, RCP 4.5 and 8.5). Then, we will compute the demands of water by different sectors and integrate water availability and demand to reach an optimal water use based on the Nexus thinking. Our results will provide decision-makers with information regarding the risks and trade-offs and will support water resources management decisions in order to allocate scarce water resources toward food or energy.

In Greek mythology, Cassandra was cursed with a prophetic knowledge of the future that no one would believe. The premise of this mythological prophet is also an apt description of the challenge facing scientists in communicating climate change. Central to addressing this challenge is the ability to examine, interpret and understand the individual scaffolding that underlies people's perception of climate change. Human-centered design incorporates a deep assessment of human needs in the design of systems and services, providing an alternative lens to engage in action towards climate change. Over the course of three separate design classes, attracting a diverse array of students from undergraduate to PhD to professional degrees, from engineers to humanists, we have explored the intersection of design education and climate change communication. In Design for a Habitable Planet, students conducted broad unstructured interviews to populate a matrix of beliefs and experiences around climate change, allowing them to bridge a perceived empathy gap. Their subjects included local fisherman, who are experiencing climate change but are ideologically opposed to the concept, and Alaska Native students who are experiencing climate change as part of a larger portfolio of challenges facing their communities. Leveraging theories from behavioral psychology, students then developed and prototyped an array of climate action campaigns, using an array of mediums from Snapchat filters to crowd-sourced climate haiku on beer labels. A unique outcome of the design process was a set of strategies intended to engage voices from all corners of the climate change debate and in turn inspire action. In Design of Data, students were challenged to design a data journalism piece highlighting positive action to address climate change. Students struggled with their pre-conceived negative bias around climate change, but after an examination of their own communities, what emerged were eight compelling stories daylighting positive and collective action to address global change. Ultimately, through our classroom experiments integrating design, behavioral psychology and climate change communication, students have not only learned to engage across differences, but we have developed a first glimpse of the power of design to inspire novel strategies to incite positive action to address climate change.

While about 17% of the adult population have significant hearing loss, we remain under-represented within academia outside of the field of Deaf Studies. One primary contributor to the leaky pipeline is lack of mentorship due to the difficulty of deaf and hard of hearing academics in recognizing one another. Hearing loss among non-signers is seldom obvious. Consequently, non-signing deaf and hard of hearing academics at predominantly hearing institutions often remain isolated without guidance on how to manage the myriad of communication challenges facing academics, such as teaching, leading group meetings, addressing questions at conferences, participating in discussions at professional meetings, and serving on grant proposal panels. Adequate solutions are often not available from our hearing health care providers nor from disability services offices, which are mandated and designed to serve undergraduate students. However, the success of all academics depends on mastering these different communication challenges. To fill the mentoring gap, we have started a blog by and for academics at all career stages with some degree of hearing loss called, “The Mind Hears”. This title derives from the Victor Hugo quote “What matters deafness of the ear when the mind hears, the one true deafness, the incurability deafness is that of the mind.” The goals of the blog are: To provide a forum for crowd-sourcing ways to minimize our challenges and share strategies for thriving in academia with hearing loss. To foster a network of deaf and hard of hearing academics who promote hearing inclusive strategies at universities. Through this blog we hope to reach deaf and hard of hearing academics all around the world, and thus reduce isolation in our community and build a community toolbox of resources and ideas. Hearing loss is variable and can affect us in many and different ways – but through this shared blog we hope to provide something of value to all of those who visit and contribute to our discussions.

First-arrival traveltime tomography (FATT) has been one of the commanding tomographic approaches for long wavelength velocity model building. Nowadays, FATT models are often used as initial models for more resolving imaging methods such as full-waveform inversion (FWI). In this context, improving the accuracy of FATT model is crucial to mitigate the nonlinearity of FWI. In spite of the widespread use of FATT at all scales (from near surface to global scale), it suffers from ill-posedness in terms of non-uniqueness of the solution due to the deficient information carried out by the sole traveltime attribute. We promote the use of the traveltime perturbation with respect to the source/receiver positions (horizontal component of the slowness vector or slope) as a supplement to the first-arrival traveltime (Tavakoli et al., 2018). For multi-component controlled-source experiments, we can generally take advantage of the fine source sampling to measure slopes by tracking local coherency over few neighboring traces in addition to traveltimes in common-receiver gathers, while slopes at the receiver position may be estimated by polarization analysis. The information of differential nature carried out by slopes yields a higher order sensitivity with respect to the subsurface parameters. We implement our first-arrival slope+traveltime (FASTT) tomography with eikonal solver and the matrix-free adjoint-state method, as previously proposed by Taillandier et al.(2009) for FATT. We illustrate the resolution power of FASTT relatively to FATT for coarse ocean bottom seismometer (OBS) acquisitions using two benchmarks based upon the EAGE/SEG Overthrust model at the exploration scale and a synthetic model of the eastern-Nankai subduction zone at the deep crustal scale (Górszczyk et al., 2018), then assess the quality of the tomographic models as initial models for FWI. We finally present an application to real OBS data collected during the SFJ experiment in the eastern Nankai Trough (Tokai area).

Community science is a collaboration between scientists and communities including their citizens and their leaders. In this collaboration, the scientists and communities together determine the questions to be studied, the approaches to be taken, and the interpretation of the results. Such a collaboration requires a foundation of scientific literacy within the community to enable both individuals and the community as whole to access the needed scientific understanding and to participate in the scientific process. It also requires that scientists and educators learn about the knowledge, values, norms, and priorities of the communities in which they are working—a kind of scientific community literacy. The EarthConnections Alliance supports the engagement of educational institutions and programs in community science while building community science literacy and scientific community literacy. The EarthConnections Alliance is formed of regional groups that are invested in linking geoscience learning and community service across grade levels within their communities as well as program partners who have expertise needed to create these learning opportunities. All members share a vision of creating learning pathways with four critical elements: 1) they connect opportunities to learn geoscience with opportunities to use this knowledge in service to the local community; 2) they link geoscience learning opportunities and learners across grade levels; 3) they use signposting and mentoring to guide and support students; and 4) they lead to local employment opportunities and geoscience-related careers. Initial funding for EarthConnections explored the creation of regional pathways in diverse sites across the country, the development of strategies and tools for supporting pathway development, and mechanisms for sharing resources and expertise within the Alliance. Over 125 individuals and groups are now engaged in this effort. Further information is available on the EarthConnections website: serc.carleton.edu/EarthConnections.html.

The Lithium Nevada Corp. Thacker Pass Project has a measured resource of 242M tonnes at 0.29% Li (~0.7M tonnes Li). The deposit is the southernmost of five known lenses hosted within intracaldera tuffaceous sediments along the west side of the McDermitt caldera, which formed by eruption of 16.4 Ma peralkaline-metaluminous tuff. Analyses of 9880 core samples (~1.5-m thick) give a mean of ~ 2500 ppm Li, with some >8800 ppm. Entire sedimentary sections in the southern and western parts of the caldera basin have high Li (1500+ ppm). Pre-caldera rocks, the McDermitt Tuff, late caldera volcanics, and unaltered tuffaceous sediments have relatively low Li (5 -140 ppm). Sediment deposition was mainly subaqueous in the closed caldera basin. Li-rich fill may have been deposited from airborne sources. Claystone comprises most of the Thacker Pass deposit and dominates Li-rich intervals. The rest is mostly feldspar-rich ash. X-ray diffraction (XRD) data from six core holes across the deposit show consistent lateral mineral zoning. A Li-rich zone (mean >4,000 ppm) mainly contains illitic clay and underlies a zone of lower Li with smectite + analcime. Based on XRD peak locations and chemistry, the closest analogs to the illitic clay are Li micas (e.g. tainiolite). Montmorillonitic clay and a basal silicified zone underlie the illitic zone. Some transitional rock of mixed-layer clay between the illite and smectite zones also has high Li. All clay has similar optical properties but SEM images show illite forms tiny hexagonal plates and smectite has no resolvable crystallinity. Calcite, albite, K-feldspar, and quartz occur in all zones, dolomite and fluorite near the top of the illite zone, and pyrite and bitumen in unoxidized rock. The Li-rich zone has relatively high K, Rb, Mo, As, and Sb. Secondary Kspar in the Li-rich zone gave an 40Ar/39Ar age of 14.87±0.05 Ma. No origin fully explains known characteristics. The presence of illite suggests a moderate temperature hydrothermal system. Release of Li from tuffaceous sediments and transport by alkaline groundwater are consistent with most mineralogy (characteristic of closed hydrologic system diagenesis) and with the Kspar date that long postdates caldera magmatism. Release of 10 ppm Li from the likely 50-200 km3 of intracaldera sediments would contribute ~1-4M tonnes Li.

Air composition of the Lewis-Clark Valley (LCV) was studied over a two-year period to investigate the effects of a local pulp paper mill on ambient air and to assess potential health risk to the community. Lewiston, Idaho and Clarkston, Washington are twin cities in the Snake River Valley bordering North-Central Idaho and Southeastern Washington, with a population of over 50,000 including the surrounding areas. The paper mill is located in North Lewiston and releases malodorous sulfur air pollutants in the LCV. The neighboring Nez Perce Tribe has conducted a couple of air studies, in 2006-2007 and the summer of 2016-17, but to date no longer term study has taken place. Our current study utilized active air sampling via sorbent tubes followed by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS) analysis to measure over 50 volatile organic compounds, hazardous air pollutants, and sulfides in ambient air (adapted from EPA Method TO-17). Seasonal, diurnal, and spatial variations in air composition were explored. In addition, monthly averaged passive air samples were collected for comparison at nearby urban areas – Boise, ID, Coeur d’Alene, ID, and Spokane, WA in 2018. In the LCV, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) were the primary sulfur compounds detected, with concentrations highest adjacent to the paper mill. However, concentrations varied considerably depending on time of day, season, location and meteorology. Seasonal observations include DMS, benzene and chloroform peaking in the summer months, while DMDS peaks in the winter. Diurnal trends show DMS and chloroform with higher values during the morning hours than later in the day. The long-term monthly samples show benzene decreasing from winter to spring, with LCV levels comparable to Coeur d’Alene and Spokane, and Boise slightly higher. In most cases, benzene levels exceed those recommended for ambient air in the state of Idaho. Sources and potential health implications will be discussed.

Immersion freezing is an important heterogeneous ice nucleation process in mixed-phase clouds. Many researches on immersion freezing focus on the parameterization using the classical nucleation theory. However, the ice nucleating abilities of the atmospheric aerosol particles are not well understood, and therefore cause difficulties of the parameterization of immersion freezing. In this study, we investigate the ice nucleating ability of Marigold pollen from the Beijing area by doing drop immersion freezing experiments in the laboratory. Marigold pollen are first mixed with pure water. A population of drops with a volume of 10 mL from the mixture are then put on a PE film in a chamber with a cooling rate of about 0.5 °C min-1. We find that the median freezing temperature of drops with pollen as ice nuclei is -17 °C. The contact angle parameterization of immersion freezing using the classical nucleation theory is also given in this study. We use the single-θ and the θ-pdf parameterization schemes to explain the data. The results show that the θ-pdf parameterization scheme is better for describing the ice nucleating behavior of the pollen in Beijing.

As a national strategic resource, trade activities of potassium resources（K） have changed its state of ownership. Futures and spot trading forms in the international market are mainly primary processed ore and deep-processed products. So, K trade can be replaced by the potassium salt trade. Its international trade will affect a country’s strategic resource management, and increase national resource security risks. Thence, it is necessary to study the evolution of international trade in K. This paper has constructed a weighted and directed complex network model of K trade using UN Comtrade 2000-2016 data and analyzed the scale and activity of international trade of K, trade relations, trade flow distribution and the importance of countries. By analyzing the international trade data of K in 224 countries, it is found that trade is active year by year and K is becoming more significant. From network density and diameter, resource allocation is more convenient. The network cluster is growing. It shows that some countries form trade groups. The correlation coefficient of degrees is less than 0, indicating that the trade relationship between small and major trade countries is enhancing. And, the reciprocal coefficient is between 0.1 and 0.35, showing that the trade order is poor. Moreover, it presents a state that the greater the country’s degree, the smaller the difference in trade flow distribution. So, resource flows in countries with more trade relations can promote a balanced distribution of K. Finally, from countries’ trade influence and hub status, Canada is a leading trade country, and the US, the Russian Federation, China and Brazil are trade-led countries. They are the main source of K flows. China, the Netherlands, the US, France and India are important hubs. So, countries should strengthen bilateral trade relations. So as to ensure the SD of international trade in K, major trading countries should focus on the exploit of K and improve the level of production and processing tech. Countries should also enhance their hub role to facilitate the flow of K. China, as a large country in agriculture and K demand, should increase self-sufficiency to reduce import dependence risks. Besides, attention should be paid to market changes in major trading countries and to reducing risks by adding the number of trade countries.

There have been numerous calls to promote reproducible research. This growing awareness coincides with major advances in data/code sharing technologies. Yet authors, journals, institutions, and funders still need to act to advance more reproducible research. Here, we suggest to view reproducibility as a continuum that includes the 1) availability of data, models, code, and directions to use the digital artifacts, 2) replication of results, and 3) reproducibility of findings. We present a simple survey tool to assess where a peer-reviewed journal article lies on the continuum. We use the tool to assess 360 random sampled articles of the 1,989 articles published in 2017 in six well-regarded hydrology and water resources journals. 49% of sampled articles had some materials available online, but just 5.6% made available all the data, models, code, and directions. For 1.6% of articles, we generated results that replicated some or all of the published results. Assessments took 5 to 14 minutes per article to determine the availability of digital artifacts and 25 to 86 minutes to replicate results (25-75% range). The availability of data, models, code, and directions differed by journal and journal policy towards data availability. From the 360 article sample, we estimate that 0.6% to 6.8% of all articles published in the six journals in 2017 can be replicated using their published artifacts (95% confidence interval). These results suggest several practices to improve the reproducibility of published research. First, authors should provide directions to use their data, models, and code in addition to the digital artifacts. Second, on author submission, journals should use a tool like ours to assess the submission’s position on the reproducibility continuum. Third, journals should formulate policies that require authors to state the intended reproducibility of their work and place relevant information in an easy-to-find article location. Fourth, journals, institutions, and funders should highlight work whose digital artifacts, results, and findings are available, replicable, and reproducible.

The past 2 decades of research has demonstrated the value of co-production as a process that creates information that is usable to decision makers. However, research has also shown that those organizations that are already larger, more technically-capable, and located closer to the sources of new information are more likely to engage in co-production with boundary organizations. The question then arises of how smaller entities, who may actually have greater need for capacity, can benefit from investments in new science aimed at improving decision making for water management. In this project we conducted 5 case studies of the information use preferences and practices among small-scale water systems (small municipalities and Water Conservancy Districts) in the Upper Colorado River Basin to understand the opportunities and constraints for the uptake of new sources of information. Like previous work, results indicated that scale, skill, understandability, and lack of capacity limited the use of available information. Furthermore, entities did not engage in co-production with knowledge-related boundary organizations to any extent. However, small water providers did consistently mention the value of contact with other water systems in the area, and the value of being able to reach out to certain key individuals who were looked to as trusted sources of opinion on current information products and trends. Managers emphasized the importance of experience in operating a water system and involvement in operations as critical factors that engendered trust in these key individuals. Finally, certain water systems were seen as leaders in the local area, and constantly mentioned as sources of information and innovative ideas. These findings suggest the importance of both key individual practitioners in pioneering and disseminating new information, as well as more broadly the role of a community of practice in reaching small water providers. Implications for boundary organizations and emerging networks are discussed.

Mixed phase clouds, consisting of ice particles and super cooled liquid droplets, predominantly found in Arctic, are poorly represented in various climate models. A unique tethered balloon campaign carrying 4π radiometer, a cloud particle imager, and a meteorological package on board was conducted in Ny-Ålesund, Norway, located high in the Arctic at 78.91°N, 11.91°E during May-June 2008. The radiometric and cloud observations at 500nm and 800nm were collected during a month long experimental campaign. A state-of-the-art discrete ordinate radiative transfer model was used to estimate optimal cloud optical properties. These optical properties are contrasted with those of the cloud parameterization in the new NOAA-GFDL AM4 model that is presently being used in the Coupled Model Intercomparison Project 6 (CMIP6). The improved simulation of cloud optical properties will aid in understanding cloud radiation feedbacks and better representation of clouds in global climate model.

Dense acquisition are more and more available in exploration and earthquake seismology. Tomographic approaches can now consider not only travel times but also the wavefront itself across the seismic network (Zhang and Thurber, 2003; Yuan et al., 2016). For dense controlled-source seismic experiments, double differences of travel times between receivers in a common-shot gather (resp between sources in a common-receiver gather) are estimated, namely the horizontal component of the slowness vector at source and receiver positions designed as slopes. These slopes associated with the two-way traveltimes are interpreted as a reflection/diffraction from a small reflector segment or diffractor are used in tomographic inversion (Lambaré, 2008; Tavakoli F. et al., 2017). Picking of locally-coherent events leads to dense volumetric dataset and hence higher-resolution tomographic results (Guillaume et al., 2008). The reflection setting introduces implicitly another class of unknowns which are scatterer positions. Resulting inverse problem is awkward due to the intrinsic coupling between velocities and scatterer positions. The first choice alternates positions and wavespeeds. The second performs the joint estimation of the two parameter classes. The third one relies on the projection of the scatterer positions subspace onto the wavespeed subspace leading to a reduced-space inversion. This reduced-space formulation can be implemented in the slope tomography using adjoint-state method. Two focusing equations, which depend on two observables among the three available ones (two-way traveltime and one slope in 2D), gives exact solutions of positions which are injected as constraints in the slope tomography (Chauris et al., 2002). These constraints explicitly enforce the positions in the velocity estimation problem, which reduces now to a mono-variate inverse problem by minimization of single-slope residuals, not yet used. 2D synthetic (see figure) and real data case studies show faster convergence toward more accurate minimizer achieved by this variable projection method compared to the alternated and joint strategies. This method, which can be extended to 3D configurations, draws also interesting perspective for the joint hypocenter-velocity inversion problem in earthquake seismology.

Climate change poses uncertain, complex, and emerging risks to local governments across the country, particularly in regions prone to flood and storm hazards. While local governments recognize the importance of finding innovative approaches to climate change adaptation, it remains a challenge for many reasons, including the high cost of policy experimentation, lack of organizational capacity, and uncertainty about the efficacy of potential adaptation strategies. These are not merely challenges of technological innovation, but also of social and policy innovation. It is increasingly recognized that collaboration is required to meet these challenges. Collaborations of various types---referred to broadly as policy networks---give organizations access to information, ideas, and other resources that may be used to adapt to climate change. Certain types of networks are hypothesized to be effective for these purposes, particularly networks that span fragmented communities and integrate different knowledge systems and resources. These types of networks tend to reduce information asymmetries and maximize the diversity of information and resources available to network actors, thus increasing capacity to manage uncertain, emerging, and complex problems. In this paper we characterize the policy network surrounding climate change adaptation in Southeast Florida that includes municipal actors as well as a diverse array of stakeholders in the public, private, and nonprofit sectors. Data are gathered using a survey of organizational representatives in the region, identified though systematic searches of organizational websites as well as nominations by other climate change professionals. Overall this study shows a complex web of collaborations where over 300 diverse actors are exchanging information about climate change and sharing resources to address adaptation. Findings demonstrate that county governments and regional nonprofit organizations, such as the Southeast Florida Regional Climate Change Compact, play a crucial role in linking disparate resources and knowledge systems in the region. These organizations help to stabilize network ties within a complex and rapidly shifting political landscape, making them instrumental for the delivery of climate adaptation services.

Arctic warming is outpacing the global rate of climate change, with up to 11 degrees C of warming projected by the year 2100 if greenhouse gas emissions follow their current trajectories. Increasing temperatures are expected to result in permafrost thaw, and the combined effects of precipitation changes, soil warming, and active layer deepening are expected to result in net soil drying. While there is widespread agreement that increasing temperatures and active layer depth will release carbon from soils, the effect on vegetative C cycling is less certain. In 2017, we conducted an experiment to examine the effects of soil drying and active layer deepening on primary productivity in Eriophorum vaginatum, a dominant circumpolar Arctic sedge, and the extent to which those effects vary across ecotypes. We harvested E. vaginatum tussocks from three sites along a latitudinal gradient in the Alaskan Arctic, placed them in pots filled with peat soil, and assigned each to one of three drying treatments. In one treatment, the soils were kept saturated with water through the growing season. In the second treatment, rain was excluded in alternating two-week cycles. In the third treatment, rain was also excluded in alternating two-week cycles, and the soil column was approximately doubled in depth to allow deeper drainage. We measured soil moisture, leaf water potential, leaf area index (LAI), leaf-level phenology, and photosynthetic capacity (Amax) in each of the tussocks. We found that the southern ecotype was affected most severely by drying, with reductions in LAI, maximum leaf length, and Amax. We found that effects were greater with rain exclusion and soil column deepening than with rain exclusion alone. However, we found no difference in leaf water potential between populations or treatments, suggesting that E. vaginatum leaves function within a fairly narrow range of moisture conditions. These results demonstrate that changes in soil moisture may affect carbon storage in Arctic vegetation, but that the magnitude of the effect may vary depending on region and ecotype.

The Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) is a data management system that provides researchers with a variety of tools to help manage data throughout the lifecycle of a project. GRIIDC was developed to fulfill the requirement that all Gulf of Mexico Research Initiative (GoMRI) funded researchers make their data publicly available. After seven years of operation and over 1,900 datasets available for download, GRIIDC has encountered many challenges, including data organization issues, researchers’ varied experience with technology, and hesitance to share data. In 2016, GRIIDC began hosting training webinars to help researchers navigate the system, submit quality data and metadata, and provide data organization best practices. As the quality of data and metadata improved, GRIIDC determined that these webinars could mitigate previous issues. In 2017, the GoMRI data policy was updated requiring that each newly funded research consortium or individual investigator complete three training sessions within specific dates of their grant agreement. The training sessions included an introduction to the GoMRI data management program, organizing data – best practices and GRIIDC submission, and how to submit data to GRIIDC. The training sessions were offered by webinar and as workshops presented at the Gulf of Mexico Oil Spill & Ecosystem Science conference. After hosting over 50 webinars, offering six workshops, and training 260 researchers, GRIIDC encountered a few issues with the required training including having to schedule individual webinars to accommodate researcher’s schedules, low attention rates, and diverse attitudes and experiences sharing data. Improvements were identified such as using software to track presentation views, making webinars more interactive, hosting additional in-person workshops, requiring a quiz at the end of the training, and allowing researchers the ability to test out of training. Even with the issues identified, GRIIDC is hopeful that the training will help researchers provide quality data submissions not only for the remaining GoMRI projects but for data they will generate in the future.

Ecosystem dynamic models have been widely used to estimate terrestrial carbon flux and to project ecosystem structure and composition over time and space, because of their efficiency over direct field measurements and easy applicability to broader spatial coverage. However, such models have also been associated with internal uncertainties, as well as complexities arising from distinct qualities of the ecosystem being analyzed. The widespread sagebrush-steppe ecosystem (dominated by Artemisia spp.) in Western North America holds high ecological and social significance, but is threatened by anthropogenic forcing factors, including impacts from invasive species, climate change, and altered fire regimes. To restore the ecosystem, land managers have focused on reducing flammable vegetation and seeding native species. However, the collective effects of restoration activities, fire, climate change, and invasive species on ecosystem dynamics are poorly understood. We applied the Ecosystem Demography (ED2) model to analyze its effectiveness in predicting plant function type (PFT) composition and ecosystem fluxes, parameterized and validated using empirical datasets for different carbon, vegetation and fire scenarios at Reynolds Creek Experimental Watershed (RCEW), Idaho, USA. We initialized ED2 with 20 x 40 grids of 1 km resolution representing and allowed PFTs to grow for 20 years to reach an equilibrium state. Results showed shrubs dominating C3 grass in a few years of time, sooner for increased CO2 and initial ecosystem condition. A separate scenario with potential fire showed significant loss in biomass within eight years of time. Results from this modeling study can improve our understanding of broad-scale ecosystem processes in sagebrush-steppe landscapes and inform land management and restoration strategies.

The South American longitudinal sector presents the unique feature of the presence of daytime equatorial electrojet currents (EEJ) and the South Atlantic Magnetic Anomaly (SAMA), where the global minimum intensity of the geomagnetic field is observed. Enhanced amplitudes are observed in the horizontal magnetic components recorded on the ground within the areas of influence of both the EEJ and the SAMA and therefore it is expected that significant enhancements of GIC magnitude also occur in these regions. We use here geomagnetic field variations data recorded by fluxgate magnetometers from the Brazilian space weather program (EMBRACE) to evaluate GIC effects during two strong geomagnetic storms in March (Dst = −222nT) and June (Dst = −204nT) 2015. Among the available geomagnetic stations, we selected those with information about the underground electrical conductivity structure and that can be approximated by 1-D models for calculation of the geoelectric field. GIC levels are estimated using a realistic local power grid model located in the central region of Brazil, artificially moved to the sites where the geomagnetic measurements are available. Maximum GIC amplitude of about 8 A was estimated at an equatorial station positioned over high resistivity underground, associated with the arrival of an interplanetary pressure pulse just behind two other pulses during the June storm. The results are also interpreted in terms of the ionospheric currents over the measurement sites and the conductivity distribution beneath these sites. It is observed that both EEJ and SAMA increase the GIC amplitudes, with the greatest effects associated with EEJ. In relation to the underlying conductivity structure, the higher GIC effects are associated with low conductance at crustal depths, with upper mantle depths showing minor effect.