Stormwater Inputs in Urban Streams: Impact and Persistence of Effects on Stream Temperature

Stream temperature is an important metric for determining the health of a stream system, and derived from complex interactions between climate, weather, and local landscape characteristics. In urban areas, stream temperature is additionally influenced by impervious surfaces as well as stormwater infrastructure that translates water quickly to stream channels. Disentangling the impacts of spatial and temporal drivers of the stream temperature regime is therefore a complex task. To improve understanding of spatial and temporal variability in stream temperatures, we combined in situ stream temperature loggers with thermal infrared (TIR) imagery collected via unmanned aerial vehicles (UAV) along a 2.25 km section of creek in Syracuse, NY. TIR imagery was used document the heterogeneity of stream temperature as impacted by a natural spring and several stormwater inputs across the stream channel and down the length of a stream for three flights in May, June, and July of 2017. Thermal heterogeneities derived from stormwater culverts were observed to persist as far as 290 m downstream from their source depending on the time of year. Reach observations and weather station data were combined with TIR imagery to calibrate a deterministic stream temperature model using a modified version of HFLUX 3.0. Stream temperatures were simulated in HFLUX for a five-day period, after a two day warm up, surrounding monthly flights using different combinations of stormwater discharge and temperature. The use of two metrics derived from the TIR data, an ‘Initial Impact’ (on stream temperature) and ‘Effect Duration’, enabled spatial model calibration alongside temporal calibration to iButton observations at the end of the reach. Discrepancies between best models fits through space and best model fits through time establish that model approaches should incorporate errors in multiple dimensions. Overall, this study demonstrates that stormwater inputs in northeastern watersheds may cool mean stream temperatures, with effects that can persist for hundreds of meters downstream. Beyond the impact of stormwater, we also show that UAV-based TIR can be particularly useful for documenting these impacts when paired with in situ sensors. Finally, we find that calibrating models in multiple dimensions can more accurately simulate spatio-temporal hydrologic processes and mixing between urban water sources and the main channel

Nonequilibrium Neutrino Oscillations in the Early Universe with an Inverted Neutrino-Mass Hierarchy

The annihilation of electron-positron pairs around one second after the big bang distorts the Fermi-Dirac spectrum of neutrino energies. We determine the distortions assuming neutrino mixing with an inverted neutrino-mass hierarchy. Nonequilibrium thermodynamics, the Boltzmann equation, and numerical integration are used to achieve the results. The various types of neutrino behavior are established as a function of masses and mixing angles.Comment: 9 pages in Latex with 6 figures (10 postscript files

The extension and application of differential analyzer technique in the solution of ordinary differential equations

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1933.MICROFICHE COPY AVAILABLE IN ENGINEERING.Vita.Includes bibliographical references (leaves 151-154).by Samuel Hawks Caldwell.Sc.D

Assessing the potential of drone-based thermal infrared imagery for quantifying river temperature heterogeneity

© 2019 Crown copyright. Hydrological Processes © 2019 John Wiley & Sons, Ltd. Climate change is altering river temperature regimes, modifying the dynamics of temperature-sensitive fishes. The ability to map river temperature is therefore important for understanding the impacts of future warming. Thermal infrared (TIR) remote sensing has proven effective for river temperature mapping, but TIR surveys of rivers remain expensive. Recent drone-based TIR systems present a potential solution to this problem. However, information regarding the utility of these miniaturised systems for surveying rivers is limited. Here, we present the results of several drone-based TIR surveys conducted with a view to understanding their suitability for characterising river temperature heterogeneity. We find that drone-based TIR data are able to clearly reveal the location and extent of discrete thermal inputs to rivers, but thermal imagery suffers from temperature drift-induced bias, which prevents the extraction of accurate temperature data. Statistical analysis of the causes of this drift reveals that drone flight characteristics and environmental conditions at the time of acquisition explain ~66% of the variance in TIR sensor drift. These results shed important light on the factors influencing drone-based TIR data quality and suggest that further technological development is required to enable the extraction of robust river temperature data. Nonetheless, this technology represents a promising approach for augmenting in situ sensor capabilities and improved quantification of advective inputs to rivers at intermediate spatial scales between point measurements and “conventional” airborne or satellite remote sensing

Futures in primary science education – connecting students to place and ecojustice

After providing a background to futures thinking in science, and exploring the literature around transdisciplinary approaches to curriculum, we present a futures pedagogy. We detail case studies from a year-long professional learning action research project during which primary school teachers developed curriculum for the Anthropocene, focusing on the topic of fresh water. Why fresh water? Living in South Australia—the driest state in the driest continent—water is a scarce and precious resource, and our main water supply, the River Murray, is in trouble. Water is an integral part of Earth’s ecosystem and plays a vital role in our survival (Flannery, 2010; Laszlo, 2014). Water literacy therefore has a genuine and important place in the school curriculum.Working with teachers and their students, the Water Literacies Project provided an ideal opportunity to explore a range of pedagogical approaches and practices which connect students to their everyday world, both now and in their possible futures, through place-based learning. We describe the use of futures scenario writing in an issues-based transdisciplinary curriculum unit on the theme of Water, driven by Year 5 teachers and their students from three primary schools: two located on the River Murray and one near metropolitan Adelaide. All three schools focused on a local wetland. The research was informed by teacher interviews, student and teacher journals, student work samples, and teacher presentations at workshops and conferences. We report on two aspects of the project: (1) the implementation of futures pedagogy, including the challenges it presented to the teachers and their students and (2) an emerging analysis of students’ views of the future and implications for further work around the futures pedagogical framework. Personal stories in relation to water, prior knowledge on the nature of water, experiential excursions to learn about water ecology and stories that examine the cultural significance of water—locally and not so locally—are featured (Lloyd, 2011; Paige & Lloyd, 2016). The outcome of our project is the development of comprehensive adventurous transdisciplinary units of work around water and connection to local place

Innovating healthcare delivery to address noncommunicable diseases in low-income settings: the example of hypertension.

London Dialogue event, The Hospital Club, 24 Endell St, London, WC2H 9HQ, London, UK, 1 December 2015 Hypertension is a global health issue causing almost 10 million deaths annually, with a disproportionate number occurring in low- and middle-income countries. The condition can be managed effectively, but there is a need for innovation in healthcare delivery to alleviate its burden. This paper presents a number of innovative delivery models from a number of different countries, including Kenya, Ghana, Barbados and India. These models were presented at the London Dialogue event, which was cohosted by the Novartis Foundation and the London School of Hygiene & Tropical Medicine Centre for Global Noncommunicable Diseases on 1 December 2015. It is argued that these models are applicable not only to hypertension, but provide valuable lessons to address other noncommunicable diseases

KOI-54: The Kepler Discovery of Tidally Excited Pulsations and Brightenings in a Highly Eccentric Binary

Kepler observations of the star HD 187091 (KIC 8112039, hereafter KOI-54) revealed a remarkable light curve exhibiting sharp periodic brightening events every 41.8 days with a superimposed set of oscillations forming a beating pattern in phase with the brightenings. Spectroscopic observations revealed that this is a binary star with a highly eccentric orbit, e = 0.83. We are able to match the Kepler light curve and radial velocities with a nearly face-on (i = 5 degrees.5) binary star model in which the brightening events are caused by tidal distortion and irradiation of nearly identical A stars during their close periastron passage. The two dominant oscillations in the light curve, responsible for the beating pattern, have frequencies that are the 91st and 90th harmonic of the orbital frequency. The power spectrum of the light curve, after removing the binary star brightening component, reveals a large number of pulsations, 30 of which have a signal-to-noise ratio greater than or similar to 7. Nearly all of these pulsations have frequencies that are either integer multiples of the orbital frequency or are tidally split multiples of the orbital frequency. This pattern of frequencies unambiguously establishes the pulsations as resonances between the dynamic tides at periastron and the free oscillation modes of one or both of the stars. KOI-54 is only the fourth star to show such a phenomenon and is by far the richest in terms of excited modes.NASA, Science Mission DirectorateNASA NNX08AR14GEuropean Research Council under the European Community 227224W.M. Keck FoundationMcDonald Observator

Stringent Constraints on Cosmological Neutrino-Antineutrino Asymmetries from Synchronized Flavor Transformation

We assess a mechanism which can transform neutrino-antineutrino asymmetries between flavors in the early universe, and confirm that such transformation is unavoidable in the near bi-maximal framework emerging for the neutrino mixing matrix. We show that the process is a standard Mikheyev-Smirnov-Wolfenstein flavor transformation dictated by a synchronization of momentum states. We also show that flavor ``equilibration'' is a special feature of maximal mixing, and carefully examine new constraints placed on neutrino asymmetries. In particular, the big bang nucleosynthesis limit on electron neutrino degeneracy xi_e < 0.04 does not apply directly to all flavors, yet confirmation of the large-mixing-angle solution to the solar neutrino problem will eliminate the possibility of degenerate big bang nucleosynthesis.Comment: 11 pages, 6 figures; minor changes to match PRD versio