Protection of Coastal Infrastructure under Rising Flood Risk

The 2005 hurricane season was particularly damaging to the United States, contributing to significant losses to energy infrastructure—much of it the result of flooding from storm surge during hurricanes Katrina and Rita. In 2012, Hurricane Sandy devastated New York City and Northern New Jersey. Research suggests that these events are not isolated, but rather foreshadow a risk that is to continue and likely increase with a changing climate. Extensive energy infrastructure is located along the U.S. Atlantic and Gulf coasts, and these facilities are exposed to an increasing risk of flooding. We study the combined impacts of anticipated sea level rise, hurricane activity and subsidence on energy infrastructure with a first application to Galveston Bay. Using future climate conditions as projected by four different Global Circulation Models (GCMs), we model the change in hurricane activity from present day climate conditions in response to a climate projected in 2100 under the IPCC A1B emissions scenario. We apply the results from hurricane runs from each model to the SLOSH model to investigate the projected change in frequency and distribution of surge heights across climates. Further, we incorporate uncertainty surrounding the magnitude of sea level rise and subsidence, resulting in more detailed projections of risk levels for energy infrastructure over the next century. Applying this model of changing risk exposure, we apply a dynamic programming cost-benefit analysis to the adaptation decision.Thanks are due to Professor Kerry Emanuel for his guidance in the application of his hurricane analysis. Any errors in its application are attributable to the authors. The authors gratefully acknowledge the financial support for this work provided by the MIT Joint Program on the Science and Policy of Global Change through a consortium of industrial sponsors and Federal grants with special support from the U.S. Department of Energy (DE-FE02-94ER61937). N. L. was supported by the NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by the University Corporation for Atmospheric Research

Water Body Temperature Model for Assessing Climate Change Impacts on Thermal Cooling

We develop and test a physically based semi-Lagrangian water body temperature model to apply climatological data and thermal pollution from river-based power plants to historical river flow data in order to better understand climate change impacts on surface water temperature and thermal power plant withdrawal allowances. The model is built for rapid assessment and use in Integrated Assessment Models. We first test the standalone model on a 190km river reach, the Delaware River, where we have detailed flow and temperature data. An R2 of 0.88 is obtained on hourly data for this initial test. Next, we integrate the standalone temperature model into a series of models—rainfall-runoff model, water demand model, water resource management model, and power plant uptake and release model—for the contiguous USA (CONUS), with about 19,000 segments total. With this system in place, we then validate the standalone water temperature model within the system for 16 river stations throughout the CONUS, where we have measured daily temperature data. The model performs reasonably well with a median R2 of 0.88. A variety of climate and emissions scenarios are then applied to the model to test regions of higher vulnerability to river temperature environmental violations, making use of output from two GCMs and six emissions scenarios focusing on projections out to 2050. We find that the two GCMs project significantly different impacts to water temperature, driven largely by the resulting changes in streamflow from the two models. We also find significantly different impacts on the withdrawal allowed by thermal power plants due to environmental regulations. Potential impacts on generation are between +3% and -4% by 2050 for the unconstrained emissions case and +3.5% to -2% for the stringent GHG mitigation policy (where 1% is equivalent to 32 TWh, or about 3 billion USD/year using 2005 electricity prices). We also find that once-through cooling plants are most vulnerable to climate change impacts, with summer impacts ranging from -0.8% to -6% for the unconstrained emissions case and +2.1% to -3.7% for the stringent GHG emissions case

Disfluency in typical and stuttered speech

MilanoThis paper discusses what happens when things go wrong in the planning and execution of running speech, comparing disfluency in typical speech with pathological disfluency in stuttering. Spontaneous speech by typical speakers is rarely completely fluent. There are several reasons why fluency can break down in typical speech. Various studies suggest that we produce disfluencies at a rate of around 6 per 100 fluent words, so a significant proportion of our utterances are disfluent in some way. Stuttering can halt the flow of speech at a much higher rate than typical disfluency. While persons who stutter are also prone to the same kinds of disfluency as typical speakers, their impairment results in the production of other forms of disfluency that are both quantitatively and qualitatively different from typical forms. In this paper, I give an overview of the causes of disfluency in both typical and stuttered speech and relate these causes to their articulatory and phonetic realisations. I show how typical and stuttered disfluencies differ in both their cause and their realisations.caslpub5323pub

Educational Experiences in Making Art: An Investigation of Process-Based Learning in the Studio

Educational Experiences in Making Art: An Investigation of Process-Based Learning in the Studio Sarah Elizabeth Lickley Using a combination of practice-led research methods and process-based learning techniques, this thesis explores the possible benefits and limitations of documentation and reflection processes in the learning environment of an artist’s studio. The researcher completed six large scale artworks while practicing rigorous documentation and reflection. An analysis through the visual means of concept mapping revealed multiple insights on the positive effects of process-based learning in the studio, as well as the nuances and difficulties of taking on this type of learning. Over the course of three months of directed studio practice, the researcher identified multiple positive effects of process-based learning. Included in these beneficial outcomes is consistent and continual artistic growth. Sustained self-directed learning is a valuable skill that can aid individual artists and students in pursuing their goals both inside and outside of the traditional education system. Other pertinent outcomes include enhanced understanding of artistic direction, heightened self-understanding and accelerated progress. The limitations of process-based learning became evident when documentation and reflection took over artistic processes, disrupting the flow of thought during the making of an artwork. The researcher emphasizes the necessity of finding balance between intuition and organization within an artistic project to ensure that process-based learning can be integrated seamlessly into an artistic practice. The findings are applied to multiple art education contexts in order to extend their applicability beyond the artist’s studio

The vulnerability of U.S. coastal energy infrastructure under climate change

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 75-77).The 2005 hurricane season was particularly damaging to the United States, contributing to significant losses to energy infrastructure -much of it a result of flooding from storm surges during hurricanes Katrina and Rita. Previous research suggests that these events are not isolated, but rather foreshadow a risk that is to continue and likely increase with a changing climate (17). Since extensive energy infrastructure exists along the U.S. Atlantic and Gulf coasts, these facilities are exposed to an increasing risk of flooding. We study the combined impacts of anticipated sea level rise, hurricane activity, and subsidence on energy infrastructure in these regions with a first application to Galveston Bay. Using future climate conditions as projected by four different Global Circulation Models (GCMs), we model the change in hurricane activity from present day climate conditions in response to a climate projected in 2100 under the IPCC A l B emissions scenario using hurricane analysis developed by Emanuel (5). We apply the results from hurricane runs from each model to the SLOSH model (Sea, Lake and Overland Surges from Hurricanes) (19) to investigate the change in frequency and distribution of surge heights across climates. Further, we incorporate uncertainty surrounding the magnitude of sea level rise and subsidence, resulting in more detailed projections of risk levels for energy infrastructure over the next century. With a detailed understanding of energy facilities' changing risk exposure, we conclude with a dynamic programming cost-benefit analysis to optimize decision making over time as it pertains to adaptation.by Megan Jeramaz Lickley.S.M.in Technology and Polic

Joint inference of CFC lifetimes and banks suggests previously unidentified emissions:Nature Communications

AbstractChlorofluorocarbons (CFCs) are harmful ozone depleting substances and greenhouse gases. CFC production was phased-out under the Montreal Protocol, however recent studies suggest new and unexpected emissions of CFC-11. Quantifying CFC emissions requires accurate estimates of both atmospheric lifetimes and ongoing emissions from old equipment (i.e. ‘banks’). In a Bayesian framework we simultaneously infer lifetimes, banks and emissions of CFC-11, 12 and 113 using available constraints. We find lifetimes of all three gases are likely shorter than currently recommended values, suggesting that best estimates of inferred emissions are larger than recent evaluations. Our analysis indicates that bank emissions are decreasing faster than total emissions, and we estimate new, unexpected emissions during 2014-2016 were 23.2, 18.3, and 7.8 Gg/yr for CFC-11, 12 and 113, respectively. While recent studies have focused on unexpected CFC-11 emissions, our results call for further investigation of potential sources of emissions of CFC-12 and CFC-113, along with CFC-11.</jats:p

How fluent is the fluent speech of people who stutter? A new approach to measuring kinematics with ultrasound

AM deposited 2020-06-22We present a new approach to the investigation of dynamic ultrasound tongue imaging (UTI) data, applied here to analyse the subtle aspects of the fluency of people who stutter (PWS). Fluent productions of CV syllables (C = /k/; V = /, i, /) from three PWS and three control speakers (PNS) were analysed for duration and peak velocity relative to articulatory movement towards (onset) and away from (offset) the consonantal closure. The objective was to apply a replicable methodology for kinematic investigation to speech of PWS in order to test Wingate's Fault-Line hypothesis. As was hypothesised, results show comparable onset behaviours for both groups. Regarding offsets, groups differ in peak velocity. Results suggest that PWS do not struggle initiating consonantal closure (onset). In transition from consonantal closure into the vowel, however, groups appear to employ different strategies expressed in increased variation (PNS) versus decreased mean peak velocity (PWS).casl30pub4219pub3-