Storm-time geomagnetic disturbances induce significant geoelectric fields within the Earth that can adversely affect the operation of electric power grids. The recently completed magnetotelluric survey supported by the NSF EarthScope program (2006-2018) has produced a large public archive of impedance tensors across much of the continental United States (US). In this work, the EarthScope tensors are convolved with long time series of geomagnetic field variation recorded at USGS observatories to obtain estimated time series of historical geoelectric fields. Integrating these geoelectric fields across power transmission lines results in time series of geomagnetically induced voltages on each power line. These voltages are analyzed statistically to construct hazard maps of the maximum voltages that could be realized in transmission lines across the US for an extreme, once in one hundred-year, geomagnetic storm. In combination with grounding resistance data and network topology, these voltage estimates can be utilized by power companies to estimate extreme geomagnetically-induced currents within their networks. These voltage estimates can provide information on which power lines and substations are most vulnerable to geomagnetic storms and can guide power companies in assessments of where to install additional protections within their grid.

Developing crops with better root system architecture and nitrogen use efficiency can lead to resilient crops capable of sustaining productivity in both optimum and stress environments. The increase in soybean global demand and its use in biodiesel and new soy-based products calls for new soybean cultivars that have higher yields, better nutritional values or desirable traits for specific use. The soybean germplasm collection at the USDA is a valuable resource in discovering novel allelic variations. This collection has not been screened extensively for the root nodule and root system architecture traits. We have already established root phenotyping platforms in our laboratory and we are proposing to screen a diverse pool of the USDA soybean collection for nodules and root system architecture traits. Availability of SNP data for this collection will let us run genome-wide analysis and identify QTLs responsible for different root traits. We will then use hairy root transformation to knockout/down some of the candidate genes in the loci identified in earlier reports and new QTLs identified in this project. This project will help us in deciphering the phenotypic variation in soybean root traits. Ultimately, better understanding of the regulatory mechanism controlling these traits can help us in developing resilient crops and a sustainable cropping system.

Crop yield is sensitive to climate change and has been projected to be negatively affected by future climate. To reduce yield loss and ensure food security in the context of climate change, it is critical to understand how climate variables interact with crop growth in agroecosystems. One important and widely used tool to study yield responses to climate is process-based modeling. However, using process-based models to simulate the climate impacts on crops is becoming challengeable as the future climate is characterized by more and more frequent extreme events, such as heatwaves, unpredictable rainfall, and droughts. Most existing crop models may not be capable of characterizing the impacts of such extreme events on crops simply because they usually do not simulate some critical processes that climate variables directly affect crop growth such as photosynthesis. Instead, they use a simplified approach–radiation-use efficiency (RUE) which is a coefficient to describe empirical relationships between intercepted radiation and biomass. The usage of RUE has simplified computation but also limited our understanding of interactions between climate variables (e.g., temperature, CO2, rainfall) and crop growth. Thus, we developed a module combining processes of radiative transfer and photosynthesis (RP) within the canopy to account for the impacts of climate variables on crop growth dynamically. Then, we integrated the RP module into a popular agricultural system model—the Environmental Policy Integrated Climate (EPIC) to assess its performance. The results show that its capabilities of predicting crop yield are comparable to the traditional RUE method. The correlation between observed and simulated biomass is 0.77 for the RUE method, while 0.76 for the RP method. But the RP method could show responses of biomass accumulation to changes in climate factors, which is almost overwhelming for RUE. For instance, the RP module could simulate how extremely high temperatures (which usually last several hours during a day) affect crop growth and also allow the EPIC to distinguish elevated CO2 impacts on C3 and C4 crops, while the default RUE method could not. Therefore, the RP module is promising to improve capabilities and extend functionalities of current process-based models, which is not only beneficial to the community of crop modeling but also enhances our ability to evaluate the impacts of climate change on the agroecosystem.

The combination of strontium (87Sr/86Sr) and uranium (234U/238U) isotopes is an especially useful tool to track and quantify mixtures of water sources in arid wetlands, where chemistry and lighter isotopic tracers are strongly influenced by evaporation and transpiration. Those isotopes were used to understand modern water supply to the Pahranagat National Wildlife Refuge (PNWR) in southern Nevada (Paces & Wurster, 2014, J. Hydrol. 517). We investigate the possibility that this isotopic combination might also track paleohydrological changes in such settings. Here, we present Sr and U isotope data for authigenic carbonates in a sediment core spanning 5800 14C cal years from Lower Pahranagat Lake (LPAH), a shallow, alkaline lake within the PNWR. Modern surface waters in the PNWR are comprised of mixtures of discharge from two high volume springs from the regional carbonate aquifer in the northern valley, and smaller amounts of local discharge from the shallow volcanic aquifer in the southern valley. Modern surface water from LPAH has U isotopic values similar to the most recently formed LPAH carbonates; however, Sr isotopic values in LPAH surface water are somewhat lower than values in those same carbonates. Combined Sr and U isotope values in Holocene LPAH carbonates fall within the range defined by the three primary spring sources and reflect varying mixtures of those sources supplying LPAH from mid-Holocene to modern time. Values in the oldest samples (~5800 14C cal yr BP) have distinct 87Sr/86Sr and 234U/238U values that nearly match the local spring end member, suggesting that LPAH water at that time was dominated by proximal volcanic aquifer sources. By ~5300–5200 14C cal yr BP, LPAH water was comprised of a nearly equal mixture of the three spring sources, marking a dramatic shift in hydrologic conditions that allowed contributions of surface flow from distal carbonate springs to the north. Values in samples from ~1,000–3,000 14C cal yr BP indicate decreased contributions from distal carbonate springs during two drought intervals; however, by 730 14C cal yr BP, surface flow from carbonate springs had resumed. Our results indicate that combined Sr and U isotopes preserve evidence of past changes in water sources in arid wetlands useful for interpreting evolving hydrologic conditions.

Climate emergency and exponential population growth threaten urban water security in cities worldwide. In the UK, London aims to build more than half a million households over the next 10 years to cope with a growing demand for housing. These new urban developments will significantly increase the consumer water demand, urban flood risk, and river water pollution levels; therefore, a sustainable approach to development is urgently required. Urban Water Neutrality (WN) has emerged as a concept to frame these concerns about rising water stresses in cities. We adapt the definition of WN as a design process aimed to first minimise the impact of every new development and then offset any remaining stresses with interventions external to the development, so the current overall impact levels are not increased after the project completion. Despite several studies related to WN, little evidence is available on how urban water neutrality might be achieved to tackle predicted pressures at city scale. In this work, we present a novel urban design and evaluation module called CityPlan. It integrates spatial data with an integrated urban water management model, enabling urban design at systems level and delivering a new index that assesses possible future scenarios. Urban form properties and urban water security indicators are improved with design options that deliver different scores of the Water Neutrality Index (WNI). The results from the WNI indicate the potential of a particular urban design scenario to achieve water neutrality and how multiple interventions should be combined at city scale. In London, CityPlan’s results suggest that it will be necessary to retrofit almost the same number of existing homes with WN design options outside the planned development areas to completely offset the forthcoming water stresses. CityPlan provides a clear vision of how water neutrality can be achieved for urban water systems and is a powerful tool for urban planners and other stakeholders to effectively promote new policies and drive sustainable development. Moreover, it provides a framework to contextualise water neutrality and its key role in urban water security.

Zonal flows in rotating systems have been previously shown to be suppressed by the imposition of a background magnetic field aligned with the direction of rotation. Understanding the physics behind the suppression may be important in systems found in astrophysical fluid dynamics, such as stellar interiors. However, the mechanism of suppression has not yet been explained. In the idealized setting of a magnetized beta plane, we provide a theoretical explanation that shows how magnetic fluctuations directly counteract the growth of weak zonal flows. Two distinct calculations yield consistent conclusions. The first, which is simpler and more physically transparent, extends the Kelvin-Orr shearing wave to include magnetic fields and shows that weak, long-wavelength shear flow organizes magnetic fluctuations to absorb energy from the mean flow. The second calculation, based on the quasilinear, statistical CE2 framework, is valid for arbitrary wavelength zonal flow and predicts a self-consistent growth rate of the zonal flow. We find that a background magnetic field suppresses zonal flow if the bare Alfvén frequency is comparable to or larger than the bare Rossby frequency. However, suppression can occur for even smaller magnetic field if the resistivity is sufficiently small enough to allow sizable magnetic fluctuations. Our calculations reproduce the η/B0^2 = const. scaling that describes the boundary of zonation, as found in previous work, and we explicitly link this scaling to the amplitude of magnetic fluctuations. These results could provide a plausible explanation for why the zonal jets in Jupiter go as deep as Juno has discovered but not any deeper.

Abstract: In Sichuan basin, the Longmaxi-Wufeng formation is rich of the shale gas, and the study of control factors of pores structure and connectivity are extremely significant for exploration of shale gas. Organic matter and inorganic matrix attribute to shale reservoir characters strongly. Though this work has been carried out by others before, it still has some arguments for this topic. In this project, we collected rock samples from oilfields, we did SEM, CO2 adsorption CH4 adsorption N2 adsorption, high pressure mercury injection, microscope observation, NMR, XRD, TOC test some related experiments. Analytical results show that TOC contents of the samples range from 0.96% to 6.12%, and the Wufeng-Longmaxi formation shale organic matter content is high. The samples porosity and permeability range from 0.49%-9.55% and 0.0006mD-0.73mD respectively, and the I/S of clay mineral amount ranges from 10%-60%. A plenty of graptolites were observed in the formation under microscope, and reflectivity of graptolites and solid bitumen can reveal that organic maturity is high in the formation. The higher the TOC percentage of sample, the higher the graptolite reflectance is. There are hydraulic fractures under microscope and SEM observation, and some of hydraulic fractures formed by stress, and some of them formed by hydrocarbon generation. Inorganic pores including bedding fracture, structural pores, intercrystalline pores, intergranular pores and dissolved pores and organic pore including corrosion pores, gas pores, bitumen spherulite pores can be observed. We observed quartz, calcite, feldspar under SEM to identify their cementation, filling, different periods’ growth, and aeolotropism. Based on these analysis data, authors inferred the shale diagenetic evolution is at the diagenetic B period, the mineral bitumen mass and solid bitumen macerals organic matters are contributed to the shale gas mainly, and by calculating the plane porosity by MATLAB, the fractal dimension is about 2.57. Pores diameters of these samples range from 1-55nm, and the maximum is 4nm. Most pores are around medium pores. In summary, shale gas migrates obeying non-Darcy flow along pores/fracture several nanometers, and gas migration affected by organic matter mainly in Wufeng-Longmaxi formation in Southeast Sichuan basin, China.

Empirical Mode Decomposition (EMD) is used to examine the relationship between precipitation and surface temperature from six regions. Three regions are defined by physiography: world, ocean, and land. The other three regions are defined by averaged precipitation: dry, normal and wet. Monthly averaged daily precipitation rate from the Global Precipitation Climatology Project are compared with average monthly surface air temperature anomalies from the Goddard Institute for Space Studies using EMD. The EMD process produces component time series referred to as intrinsic mode functions (IMFs). Theses IMFs are ordered by frequency from high to low. Eight IMFs were produced for each the time series. The first three IMFs corresponded to seasonal, semi-annual and annual variations, respectively. IMF 4 to 6 corresponded to a biennial, pentennial and decadal climate signals, respectively. IMF 7 was related to the broad 20-30 year period, with the trend being revealed in IMF 8. The time series spanned the period from January 1980 to December 2015 at monthly intervals. Temperature and precipitation time series from six sampling regions were analyzed for evidence of correlation. Results from the analysis reveal the following: (1) The EMD process reveals both linear and non-linear trends. The trends are not entirely consistent between regions though they are highly correlated. (2) Apparent wave-to-wave interactions between high and low frequency components appear to be observed in the IMF 1 and 2. These distortions appear to correspond to the troughs and peaks in the decadal cycle captured in IMF 6 and may related to the solar cycle. (3) The correlation between precipitation and temperature increases with increasing IMF number.

A new family of analytical magnetohydrostatic equilibria is presented. The methodology used to calculated these equilibria is based on work by Low (e.g. Low 1991) in the form given by Neukirch and Rastätter (1999). The equilibria have the capability of combining a non-force-free layer with a domain of linear force-free magnetic field, including a transition between these two domains. Potential applications to modelling solar magnetic fields will be discussed. Low, B.C., ApJ 370, 427 Neukirch, T. & Rastätter, L., A&A 348, 1000

The MASER (Measuring, Analysing and Simulating Radio Emissions) project provides a comprehensive infrastructure dedicated to low frequency radio emissions (typically < 50 to 100 MHz). The four main radio sources observed in this frequency are the Earth, the Sun, Jupiter and Saturn. They are observed either from ground (down to 10 MHz) or from space (down to a few kHz). Ground observatories are more sensitive than space observatories and capture high resolution data streams (up to a few TB per day for modern instruments). Conversely, space-borne instruments can observe below the ionospheric cut-off (10 MHz) and can be placed closer to the studied object. Several tools have been developed in the last decade for sharing space physcis data. Data visualization tools developed by the CDPP (http://cdpp.eu, Centre de Données de la Physique des Plasmas, in Toulouse, France) and the University of Iowa (Autoplot, http://autoplot.org) are available to display and analyse space physics time series and spectrograms. A planetary radio emission simulation software is developed in LESIA (ExPRES: Exoplanetary and Planetary Radio Emission Simulator). The VESPA (Virtual European Solar and Planetary Access) provides a search interface that allows to discover data of interest for scientific users, and is based on IVOA standards (astronomical International Virtual Observatory Alliance). The University of Iowa also develops Das2server that allows to distribute data with adjustable temporal resolution. MASER is making use of all these tools and standards to distribute datasets from space and ground radio instruments available from the Observatoire de Paris, the Station de Radioastronomie de Nançay and the CDPP deep archive. These datasets include Cassini/RPWS, STEREO/Waves, WIND/Waves, Ulysses/URAP, ISEE3/SBH, Voyager/PRA, Nançay Decameter Array (Routine, NewRoutine, JunoN), RadioJove archive, swedish Viking mission, Interball/POLRAD… MASER also includes a Python software library for reading raw data. This work is supported by CDPP, CNES, PADC and Europlanet-2020-RI. The Europlanet 2020 Research Infrastructure project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654208.

We report the results of our investigations on ionospheric effects potentially caused by the 15 February 2013 Chelyabinsk meteor explosion. We used the observation data from a number of digisonde stations located in Europe and Russia to detect the traveling ionospheric disturbances (TIDs) likely to have been caused by the meteor explosion. We found that certain characteristic signatures of the TIDs can be identified in individual ionogram records, mostly in the form of Y‐forking/splitting of the ionogram traces. Based on the arrival times of the disturbances, we have inferred the overall propagation speed of the TIDs from Chelyabinsk to be 171 ± 14 m/s. In addition to the natural fulfillment of scientific endeavors, this work also highlights the importance of maintaining the mastery of ionosondes as ionospheric diagnostic instruments (in terms of operation, data analysis, representation, and interpretation) for many generations of space researchers to come.

The Younger Dryas (YD) in Bay of Islands, Newfoundland is characterized by major changes in both pollen and dinocyst assemblages, which translate into large drops in air and sea surface temperatures and sea surface salinity. Changes in vegetation are similar with those observed in Newfoundland lakes. Reconstructed air temperature shows a 7ºC drop at the time of the YD, an amplitude comparable to changes recorded in northeastern North America. Changes observed in dinoflagellate cyst assemblages are also like those at nearby sites from the Gulf of St. Lawrence and Laurentian Channel. Sea surface dropped by 7ºC, salinity by 4 psu and sea ice cover duration increased by 7 months. The YD period in eastern North America was traditionally defined by changes in sediments and pollen records. Our records show that the cooling in sea surface and air temperatures started 250 and 110 years before the start of the YD as defined by radiocarbon dates and pollen zones. By having exceptionally high resolution records for both terrestrial and marine conditions in the same core, we can show that there is a 140 years delay between ocean and atmosphere. We speculate that the major lithological and vegetation changes observed in lakes around the time of the YD period in eastern North America might actually represent the full impacts of the cooling, since the cooling trend actually started before the start of the YD period.

Formal data citation is a growing practice increasingly required by scientific journals. Roughly a decade ago, the Federation of Earth Science Information Partners (ESIP) began developing formal guidelines for data citation including acknowledgement of authors and archives and careful use of persistent identifiers (PIDs). Many Earth science data centers now provide formal citation text and PIDs for their data sets, typically a Digital Object Identifier (DOI). A central purpose of data citation (amongst many) is to aid scientific reproducibility through direct, unambiguous reference to the precise data used in a particular study, i.e., to aid provenance tracking. How has that worked in practice? ESIP is now in the process of revising and updating their guidelines and seeks to ensure that data citation meets its stated purpose. This presentation explores whether and how formal citation and the the use of PIDs for data sets has improved the tracking of data provenance. For example, is there is some commonality in the nature and granularity of objects that are assigned PIDs? We review how the guidelines are being revised to further enhance the transparency and reusability of data.

Reliable, accurate, and affordable linear motion systems for agricultural applications are currently not easily accessible due to their elevated cost. Most systems available to the public have price tags in the thousands and their dimensions cannot be easily customized. Current systems have a max length of about ten meters and for a typical greenhouse application, the length may not be sufficient. The price of the system increases with an increase in length and with a base price in the thousands it becomes almost impractical to buy a system for such application. The HyperRail is a modular linear motion system with a repeatability of 2mm and current top speed of 100mm/s. An advantage this system has is its ability to increase or decrease the length of system with minimum effort and nominal increase in price. The HyperRail can be mounted on a set of tripods or directly on the structure of a building such as a greenhouse. The base price for a three-meter system, on tripods, is US$240 and an additional US$45 for each additional one-and-a-half meter. The HyperRail was designed for the use of hyperspectral imaging but can be adapted for other sensor systems. We report on a nine-meter study over pine seedlings infected with a virus. A push-broom hyperspectral camera (Headwall Nano) was mounted on the carriage of the system imaging the seedlings. The rail is currently being adapted to an environmental sensor suite that will monitor CO2, luminosity, humidity, temperature, and the concentration of dust. The HyperRail also includes bidirectional-wireless communication between the drive and the carriage; this means that the sensor suite can operate autonomously and communicate to the HyperRail drive to move to a specific location and take measurements. This system includes a graphical user interface for users who are unfamiliar with programming but could also be used through a command line interface for individuals that want to work the code and see the effects of the changes immediately. This system was developed at Oregon State University’s OPEnS Lab, here is a link to the project page for more detailed information. URL for project page: http://www.open-sensing.org/hyper-rail/

The Piacenzian (Late Pliocene) represents a natural laboratory within which frequency and magnitude of environmental changes during a period of past global warmth can be analyzed, climate models can be tested, and results can be placed in a context to better prepare for future change. We focus on the North Atlantic and both generate new and incorporate existing faunal assemblage and alkenone data from DSDP Sites 552 and 606, ODP Sites 662, 981, 982, and 999, and IODP Sites 1307, 1308 and 1313. In addition, cores and outcrop material containing Piacenzian sediments from the Atlantic Coastal Plain of Virginia, USA, are included. These data allow us to characterize regional changes in temperature, salinity, upwelling, productivity, and diversity, associated with climate transitions, and make nuanced reconstructions of mid-Piacenzian conditions within a high-resolution temporal framework between ~3.40 and ~3.15 Ma, inclusive of Marine Isotope Stages M2 through KM5. Our results indicate the slope of the North Atlantic sea surface temperature gradient is a robust feature of the Late Pliocene and we confirm a temperature anomaly (Pliocene minus pre-industrial) little to no change at the equator to >6° C near 60° North, during Marine Isotope Stage (MIS) KM5c (3.21 Ma – 3.20 Ma). The M2-M1 transition is accompanied by warming, rapid sea-level rise, reorganization of planktonic foraminifer assemblages, decreases in productivity and increase in zooplankton diversity. Abundance changes in stenohaline taxa document repeated freshening of the Caribbean by low latitude Pacific water associated with brief re-openings of the Central American Seaway. The Gulf Stream – North Atlantic Drift migrated to a more northerly position during both the M2-M1 and KM6-KM5 transitions. Preliminary comparison of these results to climate simulations produced by the second phase of the Pliocene Model Inter-comparison Project (PlioMIP2) indicates model output and reconstructed environmental data are in closer agreement than previous data-model comparisons. We attribute this to a combination of improved Pliocene Research, Interpretation and Synoptic Mapping (PRISM4) boundary conditions, and the refined stratigraphic window used for verification, compared to PRISM3.

Unmanned aerial vehicles (UAV) have been increasingly used for field data collection and remote sensing purposes. Their ease of use, ability to carry sensors and cameras, low cost, and precise maneuverability and navigation makes them a versatile tool for a field researcher. Procedures and instrumentation to use UAVs in the field are largely undefined, especially for atmospheric and hydrologic applications. A field study was conducted to test the UAV’s ability to collect atmospheric data in order to locate and analyze the canopy boundary layer (CBL) above a Costa Rican tropical montane rainforest. This study aims to give further insight on the changes of the CBL throughout the day and for atmospheric comparison to land development. Through the study, it was found that there was little previously defined procedures and preferred instrumentation that directly applied to the UAV field study. Because of this, the methodology of using an UAV for atmospheric and CBL remote sensing and data collection was developed and refined by testing and comparing precision and performance of sensors and executing systematic flight patterns throughout the day. The UAV allowed for quick and specific access to sampling locations and for all of the variables to be measured by sensors over vertical profiles. Flights were scheduled at different locations throughout the day over the Texas A&M Soltis Center and surrounding forest in San Isidro, Costa Rica. Vertical profiles were also measured over the Soltis Center grounds to determine how development has affected the presence of the CBL. The UAV was successful in gathering data above the forest canopy and the Soltis Center at varying elevations during clear and cloudy conditions. The procedure produced reliably consistent vertical profiles over small domains in space and time, validating the general approach. The technique also identified unique profiles at spatially and temporally distinct sample sites including response to meteorological events. These findings suggest a healthy ability to diagnose CBL characteristics of interest. It was also found that there is a distinct increase in temperature and dew point over land development when compared to over forest. Future studies include flights at other locations and determining preferred instrumentation for UAV atmospheric data collection.

Several winters of the 2010s have brought to many midlatitude regions periods of extreme cold relative to the past few years and even decades. Further, it is suggested that melting of Arctic sea ice has increased the likelihood of persistent extreme weather conditions in the northern midlatitudes and the number of cold winter days. Here, estimates of warming in annual minimum temperature are updated and extended to all land areas where station temperature records are available, with emphasis on the midlatitudes. Annual minimum temperatures have warmed faster than mean temperatures in seasonally cold land regions and have already exceeded a 2 K warming threshold over the midlatitudes, but have warmed at about the same rate as mean temperatures in tropical climates. Recent regionally cold winters did not significantly deviate from the established warming trend and were within the range of interannual variability seen in the past. These findings have implications for contextualizing extreme winter weather, validating climate model projections of the consequences of sea ice loss, and guiding adaptation to shifting hardiness zones of perennial cultivars and the spread of pest and invasive species.

Northern high latitudes are projected to get warmer and wetter in the future which will affect rates of permafrost thaw and the mechanisms by which thaw occurs. To better understand these changing thaw dynamics, we instrumented an isolated permafrost plateau in south-central Alaska with climate conditions that currently mirror those expected in more northern permafrost regions in the future. Using preliminary 2019 measurements of temperature from the soil surface into permafrost, depth to frost table, water level, groundwater temperature, and meteorological variables, we tracked soil and permafrost warming throughout the season, and identified how environmental factors, such as water table elevation, microtopography, and warm rain events, affected rates of warming and thaw. Additionally, we present the extent of permafrost degradation since the last observations at this site in 2015. Permafrost thaw and resultant landscape change has a net warming effect on the climate. Understanding of the environmental factors that lead to thaw and rates at which permafrost will thaw under future climate conditions will allow for better preparation, modeling, and policy making for the future.