Ubiquitous energy storage

This paper presents a vision of a future power system with "ubiquitous energy storage", where storage would be utilized at all levels of the electricity system. The growing requirement for storage is reviewed, driven by the expansion of distributed generation. The capabilities and existing applications of various storage technologies are presented, providing a useful review of the state of the art. Energy storage will have to be integrated with the power system and there are various ways in which this may be achieved. Some of these options are discussed, as are commercial and regulatory issues. In two case studies, the costs and benefits of some storage options are assessed. It is concluded that electrical storage is not cost effective but that thermal storage offers attractive opportunities

Innovations in (U–Th)/He, Fission Track, and Trapped Charge Thermochronometry with Applications to Earthquakes, Weathering, Surface‐Mantle Connections, and the Growth and Decay of Mountains

A transformative advance in Earth science is the development of low‐temperature thermochronometry to date Earth surface processes or quantify the thermal evolution of rocks through time. Grand challenges and new directions in low‐temperature thermochronometry involve pushing the boundaries of these techniques to decipher thermal histories operative over seconds to hundreds of millions of years, in recent or deep geologic time and from the perspective of atoms to mountain belts. Here we highlight innovation in bedrock and detrital fission track, (U–Th)/He, and trapped charge thermochronometry, as well as thermal history modeling that enable fresh perspectives on Earth science problems. These developments connect low‐temperature thermochronometry tools with new users across Earth science disciplines to enable transdisciplinary research. Method advances include radiation damage and crystal chemistry influences on fission track and (U–Th)/He systematics, atomistic calculations of He diffusion, measurement protocols and numerical modeling routines in trapped charge systematics, development of 4He/3He and new (U–Th)/He thermochronometers, and multimethod approaches. New applications leverage method developments and include quantifying landscape evolution at variable temporal scales, changes to Earth\u27s surface in deep geologic time and connections to mantle processes, the spectrum of fault processes from paleoearthquakes to slow slip and fluid flow, and paleoclimate and past critical zone evolution. These research avenues have societal implications for modern climate change, groundwater flow paths, mineral resource and petroleum systems science, and earthquake hazards

Unprecedented 21st century drought risk in the American Southwest and Central Plains

In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the later half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100–1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium

Evaluation of Aerosol Mixing State Classes in the GISS Modele-matrix Climate Model Using Single-particle Mass Spectrometry Measurements

Aerosol particles in the atmosphere are composed of multiple chemical species. The aerosol mixing state, which describes how chemical species are mixed at the single-particle level, provides critical information on microphysical characteristics that determine the interaction of aerosols with the climate system. The evaluation of mixing state has become the next challenge. This study uses aerosol time-of-flight mass spectrometry (ATOFMS) data and compares the results to those of the Goddard Institute for Space Studies modelE-MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) model, a global climate model that includes a detailed aerosol microphysical scheme. We use data from field campaigns that examine a variety of air mass regimens (urban, rural, and maritime). At all locations, polluted areas in California (Riverside, La Jolla, and Long Beach), a remote location in the Sierra Nevada Mountains (Sugar Pine) and observations from Jeju (South Korea), the majority of aerosol species are internally mixed. Coarse aerosol particles, those above 1 micron, are typically aged, such as coated dust or reacted sea-salt particles. Particles below 1 micron contain large fractions of organic material, internally-mixed with sulfate and black carbon, and few external mixtures. We conclude that observations taken over multiple weeks characterize typical air mass types at a given location well; however, due to the instrumentation, we could not evaluate mass budgets. These results represent the first detailed comparison of single-particle mixing states in a global climate model with real-time single-particle mass spectrometry data, an important step in improving the representation of mixing state in global climate models

Model-dependent spatial skill in pseudoproxy experiments testing climate field reconstruction methods for the Common Era

The spatial skill of four climate field reconstruction (CFR) methods is investigated using pseudoproxy experiments (PPEs) based on five last millennium and historical simulations from the Coupled and Paleo Model Intercomparison Projects Phases 5 and 3 (CMIP5/PMIP3) data archives. These simulations are used for the first time in a PPE context, the frameworks of which are constructed to test a recently assembled multiproxy network and multiple CFR techniques. The experiments confirm earlier findings demonstrating consistent methodological performance across the employed methods and spatially dependent reconstruction errors in all of the derived CFRs. Spectral biases in the reconstructed fields demonstrate that CFR methods can alone alter the ratio of spectral power at all locations in the field, independent of whether there are any spectral biases inherent in the underlying pseudoproxy series. The patterns of spectral biases are model dependent and indicate the potential for regions in the derived CFRs to be biased by changes in either low or high-frequency spectral power. CFR methods are also shown to alter the pattern of mean differences in the tropical Pacific during the Medieval Climate Anomaly and the Little Ice Age, with some model experiments indicating that CFR methodologies enhance the statistical likelihood of achieving larger mean differences between independent 300-year periods in the region. All of the characteristics of CFR performance are model dependent, indicating that CFR methods must be evaluated across multiple models and that conclusions from PPEs should be carefully connected to the spatial statistics of real-world climatic fields

Measurements of Isoprene-Derived Organosulfates in Ambient Aerosols by Aerosol Time-of-Flight Mass Spectrometry—Part 2: Temporal Variability and Formation Mechanisms

Organosulfate species have recently gained attention for their potentially significant contribution to secondary organic aerosol (SOA); however, their temporal behavior in the ambient atmosphere has not been probed in detail. In this work, organosulfates derived from isoprene were observed in single particle mass spectra in Atlanta, GA during the 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) and the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS). Real-time measurements revealed that the highest organosulfate concentrations occurred at night under a stable boundary layer, suggesting gas-to-particle partitioning and subsequent aqueous-phase processing of the organic precursors played key roles in their formation. Further analysis of the diurnal profile suggests possible contributions from multiple production mechanisms, including acid-catalysis and radical-initiation. This work highlights the potential for additional SOA formation pathways in biogenically influenced urban regions to enhance the organic aerosol burden

Genetic comparison of water molds from embryos of amphibians Rana cascadae, Bufo boreas and Pseudacris regilla

Water molds that cause the disease saprolegniasis have been implicated in widespread mortality of amphibian embryos. However, because of the limitations of traditional identification methods, water mold species involved in die-offs or utilized in ecological studies often remain unidentified or identified only as Saprolegnia ferax. Furthermore, water mold taxonomy requires revision, so very distinct organisms may all be called S. ferax. Recent DNA-based studies indicate that the diversity of water molds infecting amphibian embryos is significantly higher than what was previously known, but these studies rely on culture methods, which may be biased towards taxa that grow best under laboratory conditions. In this study, total embryo-associated DNA was extracted from 3 amphibian species in a pond in central Washington, USA. The internal transcribed spacer (ITS) region of DNA was amplified with primers capable of amplifying a broad array of eukaryotic microorgansisms, and was used to construct clone libraries. Individual clones were sequenced and relationships among newly recovered sequences and previously studied taxa were analyzed using phylogenetics. These methods recovered several new taxa in association with amphibian embryos. Samples grouped into 11 distinct phylotypes with ITS sequence differences ranging from 4 to 28%. The water mold communities recovered differed among Rana cascadae, Bufo boreas, and Pseudacris regilla egg masses. Furthermore, the diversity of water molds increased as egg masses aged, and members comprising this diversity changed over time

Coupling of vortex breakdown and stability in a swirling flow

Swirling flows are ubiquitous over a large range of length scales and applications including micron-scale microfluidic devices up to geophysical flows such as tornadoes. As the viscous dissipation, shear, and centrifugal stresses interact, such flows can often exhibit unexpected fluid dynamics. Here, we use microfluidic experiments and numerical simulations to study the flow in a vortex T-mixer: a T-shaped channel with staggered, offset inlets. The vortex T-mixer flow is characterized by a single dominant vortex, the stability of which is closely coupled to the appearance of vortex breakdown. Specifically, at a Reynolds number of Re≈90, a first vortex breakdown region appears in the steady-state solution, rendering the vortex pulsatively unstable. A second vortex breakdown region appears at Re≈120, which restabilizes the vortex. Finally, a third vortex breakdown region appears at Re≈180, which renders the vortex helically unstable. Thus, a counterintuitive flow regime exists for the vortex T-mixer in which increasing the Reynolds number has a stabilizing effect on the steady-state flow. The pulsatively unstable vortex evolves into a periodically pulsating state with a Strouhal number of St≈0.5, and the helically unstable vortex evolves into a helically oscillating state with St≈1.75. These transitions can be explained within the framework of linear hydrodynamic stability. In addition, the vortex T-mixer flow exhibits multistability; multiple flow states are stable over various ranges of Re, including a narrow range of tristability for 160≤Re≤170, in which the steady state, the pulsatile oscillation, and the helical oscillation are all stable. This study provides experimental and numerical evidence of the close coupling between vortex breakdown and flow stability, including the restabilization of the flow with increasing Reynolds number due to the appearance of a vortex breakdown region, which will provide new insights into how vortex breakdown can affect the stability of a swirling flow

Paleoclimate constraints on the spatiotemporal character of past and future droughts

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 33(22), (2020): 9883-9903, https://doi.org/10.1175/JCLI-D-20-0004.1.Machine-learning-based methods that identify drought in three-dimensional space–time are applied to climate model simulations and tree-ring-based reconstructions of hydroclimate over the Northern Hemisphere extratropics for the past 1000 years, as well as twenty-first-century projections. Analyzing reconstructed and simulated drought in this context provides a paleoclimate constraint on the spatiotemporal characteristics of simulated droughts. Climate models project that there will be large increases in the persistence and severity of droughts over the coming century, but with little change in their spatial extent. Nevertheless, climate models exhibit biases in the spatiotemporal characteristics of persistent and severe droughts over parts of the Northern Hemisphere. We use the paleoclimate record and results from a linear inverse modeling-based framework to conclude that climate models underestimate the range of potential future hydroclimate states. Complicating this picture, however, are divergent changes in the characteristics of persistent and severe droughts when quantified using different hydroclimate metrics. Collectively our results imply that these divergent responses and the aforementioned biases must be better understood if we are to increase confidence in future hydroclimate projections. Importantly, the novel framework presented herein can be applied to other climate features to robustly describe their spatiotemporal characteristics and provide constraints on future changes to those characteristics.This material is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement 1852977. JAF was also supported by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy's Office of Biological & Environmental Research (BER) via National Science Foundation IA 1844590. JS was supported in part by the U.S. National Science Foundation through Grants AGS-1602920 and AGS-1805490, and by the National Oceanic and Atmospheric Administration by Grant NA20OAR4310425. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups (listed in Table 1) for producing and making available their model output. For CMIP, the U.S. Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portal. We thank the editor and two reviewers for comments that greatly improved the quality of this manuscript. This is SOEST Publication No. 11116 and LDEO Publication No. 8450.2021-04-1

Identification of possible intense historical geomagnetic storms using combined sunspot and auroral observations from East Asia

Comprehensive catalogues of ancient sunspot and auroral observations from East Asia are used to identify possible intense historical geomagnetic storms in the interval 210 BC-AD 1918. There are about 270 entries in the sunspot catalogue and about 1150 entries in the auroral catalogue. Special databases have been constructed in which the scientific information in these two catalogues is placed in specified fields. For the purposes of this study, an historical geomagnetic storm is defined in terms of an auroral observation that is apparently associated with a particular sunspot observation, in the sense that the auroral observation occurred within several days of the sunspot observation. More precisely, a selection criterion is formulated for the automatic identification of such geomagnetic storms, using the oriental records stored in the sunspot and auroral databases. The selection criterion is based on specific assumptions about the duration of sunspot visibility with the unaided eye, the likely range of heliographic longitudes of an energetic solar feature, and the likely range of transit times for ejected solar plasma to travel from the Sun to the Earth. This selection criterion results in the identification of nineteen putative historical geomagnetic storms, although two of these storms are spurious in the sense that there are two examples of a single sunspot observation being associated with two different auroral observations separated by more than half a (synodic) solar rotation period. The literary and scientific reliabilities of the East Asian sunspot and auroral records that define the nineteen historical geomagnetic storms are discussed in detail in a set of appendices. A possible time sequence of events is presented for each geomagnetic storm, including possible dates for both the central meridian passage of the sunspot and the occurrence of the energetic solar feature, as well as likely transit times for the ejected solar plasma. European telescopic sunspot drawings from the seventeenth century are also used to assess the credibility of some of the later historical geomagnetic storms defined solely by the East Asian sunspot and auroral records. These drawings cast doubt on a few of the associations between sunspot and auroral observations based entirely on the oriental records, at least to the extent that the occidental drawings provide a more realistic date for central meridian passage of the sunspot actually associated with a particular auroral observation. Nevertheless, on those occasions for which European sunspot drawings are available, the dates of all the pertinent East Asian sunspot and auroral observations are corroborated, apart from just one Chinese sunspot observation. The ancient historical observations of sunspots and aurorae are discussed briefly in terms of modern observations of great geomagnetic storms