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Review: David Paterson, Fair Seed-Time: Robert Evans, Francis Newdigate and the Making of George Eliot
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Particle-in-Cell Simulations of Characteristics of Rising-Tone Chorus Waves in the Inner Magnetosphere
Get PDFWhistler mode chorus waves in the Earth's inner magnetosphere are usually composed of discrete elements, and each element can be characterized by the following properties: the amplitude, the duration, the frequency span, and the frequency chirping rate. Using a one-dimensional (1-D) particle-in-cell (PIC) simulation code, we study the dependence of these properties of a rising-tone chorus on the number densityn(heq)/n(c0)and temperature anisotropyA(T)of energetic electrons at the magnetic equator. The whistler waves are first excited around the magnetic equator by anisotropic energetic electrons and then develop into a rising-tone chorus when they leave away from the equator. During the propagation toward the pole, the rising-tone chorus with nearly constant frequency span first enhances and then decays. Its frequency chirping rate declines in the early stage and then gradually increases. Meanwhile, the chorus duration is quite the opposite due to propagation effect. Over a suitable range ofn(heq)/n(c0)to generate rising-tone chorus, the frequency chirping rate of the excited rising-tone chorus first increases and then saturates, while its saturated amplitude, duration, and frequency span have a rising tendency with the increasingn(heq)/n(c0). As forA(T), the frequency chirping rate of the generated rising-tone chorus is increasing with the increase ofA(T)that is consistent with prediction of nonlinear theory, while the duration is just the opposite. Our simulation study can give a further understanding of the generation and propagation of rising-tone chorus waves.PublishedYe
Semiautomated Identification and Characterization of Dunes at Hargraves Crater, Mars
Get PDFThe Mars Global Digital Dune Database (MGD(3)) contains information on Martian dune fields and prepared manually from the Thermal Emission Imaging System (THEMIS; 100 m/pixel) images. Although the MGD(3)outlines dune fields, it overlooks the recognition of smaller dune forms. This paper aims to identify individual dunes from a semiautomated object-based image analysis technique and characterize dune materials at Hargraves crater, Mars. MGD(3)would benefit to be updated for an improved understanding of the Martian surface and its atmospheric mechanisms at a local scale. An object-based image analysis technique was applied here to the Context Camera (CTX; 6 m/pixel) data set to extract dune data in a more efficient, reliable, and accurate fashion. This study is a test case in validating a remote sensing method that has wide applicability to the entire Martian surface resulting in an update to the dune database at a higher spatial resolution-providing a better understanding of surface and atmospheric behavior of Mars at the local scale. We also explored the wind flow and dune stability-presenting an insight into the dune modification mechanism-within the crater. The prevailing wind inside the crater flows to the west-northwest. The dunes are labeled as active (stability index of 2) and do not appear to have been influenced by subsurface water ice or volatiles. We emphasize that the technique used here has a wide prospect in temporal monitoring of dune sediment flux, dune migration or erosion rates, improving near-surface airflow modeling, and dune stability analysis. Plain Language Summary The Mars Global Digital Dune Database (MGD3) contains morphologic information on Martian dune fields. MGD3 has various science applications including atmospheric circulation modeling, planetary climate change, mechanical weathering processes, and future rover lander missions to Mars. However, the database was prepared manually through visual photointerpretation from low-resolution satellite images of 100 m/pixel and, consequently, overlooked the recognition of smaller dune forms. Thus, MGD3 would benefit to be updated for an improved understanding of the Martian surface and its atmospheric mechanisms including near-surface wind patterns at a local scale as opposed to the global scale. We used a semiautomated object-based image analysis (OBIA) technique from higher-resolution images of similar to 6 m/pixel-more than 10 times higher spatial resolution compared to the previous imagery. Using the technique, we extracted individual dunes at Hargraves crater in a more efficient, reliable, and accurate fashion. The validated and accurate result in this study indicates the applicability of the OBIA method for the entire surface of Mars. Thus, the application OBIA method will be a great improvement for futures studies on Martian (and terrestrial) dune fields including temporal monitoring with better estimates of sediment flux, dune migration or erosion rates, and improving near-surface airflow modeling.PublishedYe
Multi-approach synergic investigation between land surface temperature and land-use land-cover
Get PDFRapid urban expansion and associated land-use land-cover (LULC) change in India have emerged as a
serious environmental threat that accelerates the impacts of urban heat island intensity (UHII). Three
independent investigations have been conducted in this study using a series of Landsat data. The
objectives of this work are: (1) To predict the near-future LULC scenario using an integrated model; (2)
To understand the connection between band mean for particular LULC class with LST; (3) To analyze
the temporal relationship between different types of built-up clusters and LST. The LULC and LST maps
reveal that LST increases from 27.01 to 33.86C, whereas built-up areas rise from 6.93% to 27.10%
during 1988–2018, respectively. We observed that the near-future LULC scenario of KMA shows a huge
expansion of built-up areas paid by decreased vegetation and open spaces. A clear significant correlation
has been found between band mean and LST in all three Landsat sensors with the R2 = 0.84; p\0.02 for
Landsat 5 TM, R2 = 0.91 and 0.99; p\0.01 and 0.00 for Landsat 7 ETM+, and R2 = 0.88; p\0.01 for
Landsat 8 OLI in connection to our second objective. However, no agreement has been found between
different built-up clusters and LST over 30 years of observation. For the Brst time, this study established
the interconnectivity between bands of Landsat sensors and LST. The temporal relationship between
different built-up clusters and LST have reviled also for the Brst time. Beside this, the rising rate of builtup areas was observed by the integrated model. Such alarming condition demands immediate attention to
sustainable, and scientiBc land use regulations under new urbanism policy.Ye
Cara Bray, George Eliot, and The Animal World
No full textArticle from the George Eliot Review, digitized and hosted by the George Eliot Review Online.Publishe
Comparison of probabilistic post-processing approaches for improving numerical weather prediction-based daily and weekly reference evapotranspiration forecasts
Get PDFReference evapotranspiration (ET0) forecasts play an important role in agricultural, environmental, and water management. This study evaluated probabilistic post-processing approaches, including the nonhomogeneous Gaussian regression (NGR), affine kernel dressing (AKD), and Bayesian model averaging (BMA) techniques, for improving daily and weekly ET0 forecasting based on single or multiple numerical weather predictions (NWPs) from the THORPEX Interactive Grand Global Ensemble (TIGGE), which includes the European Centre for Medium- Range Weather Forecasts (ECMWF), the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS), and the United Kingdom Meteorological Office (UKMO) forecasts. The approaches were examined for the forecasting of summer ET0 at 101 US Regional Climate Reference Network stations distributed all over the contiguous United States (CONUS). We found that the NGR, AKD, and BMA methods greatly improved the skill and reliability of the ET0 forecasts compared with a linear regression bias correction method, due to the considerable adjustments in the spread of ensemble forecasts. The methods were especially effective when applied over the raw NCEP forecasts, followed by the raw UKMO forecasts, because of their low skill compared with that of the raw ECMWF forecasts. The post-processed weekly forecasts had much lower rRMSE values (between 8 % and 11 %) than the persistence-based weekly forecasts (22 %) and the post-processed daily forecasts (between 13 % and 20 %). Compared with the single-model ensemble, ET0 forecasts based on ECMWF multi-model ensemble ET0 forecasts showed higher skill at shorter lead times (1 or 2 d) and over the southern and western regions of the US. The improvement was higher at a daily timescale than at a weekly timescale. The NGR and AKD methods showed the best performance; however, unlike the AKD method, the NGR method can post-process multi-model forecasts and is easier to interpret than the other methods. In summary, this study demonstrated that the three probabilistic approaches generally outperform conventional procedures based on the simple bias correction of single-model forecasts, with the NGR post-processing of the ECMWF and ECMWF–UKMO forecasts providing the most cost-effective ET0 forecasting.PublishedYe
Cervantes, George Eliot, and Milan Kundera's The Art of the Novel: An Introduction to a Panel Discussion
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Automated Phonetic Transcription Grading Tool
Get PDFThe Automated Phonetic Transcription Grading Tool (APTgt) is an online Learning Management System (LMS) that facilitates the comparison of phonetic transcriptions for instruction and clinical training purposes. It uses an embedded IPA graphical keyboard for transcription input. A custom edit distance algorithm aligns transcriptions in an intuitive way and then calculates differences quantitatively. This allows for objective scoring of transcriptions of even severely impaired productions, which may be difficult to score via traditional comparison methods. APTgt also includes support for comparing narrow phonetic transcriptions with diacritics.
Contact the Technologies for Speech Language Pathology Research Lab at [email protected] for registration information.N
Data for: Ecologically relevant thermal fluctuations enhance offspring fitness: biological and methodological implications for studies of thermal developmental plasticity
No full textNatural thermal environments are notably complex and challenging to mimic in controlled studies. Consequently, our understanding of the ecological relevance and underlying mechanisms of organismal responses to thermal environments is often limited. For example, studies of thermal developmental plasticity have provided key insights into the ecological consequences of temperature variation, but most laboratory studies use treatments that do not reflect natural thermal regimes. While controlling other important factors, we compared the effects of naturally fluctuating temperatures to commonly used laboratory regimes on development of lizard embryos and offspring phenotypes and survival. We incubated eggs in 4 treatments – 3 that followed procedures commonly used in the literature, and one that precisely mimicked naturally fluctuating nest temperatures. To explore context-dependent effects, we replicated these treatments across two seasonal regimes: relatively cool temperatures from nests constructed early in the season and warm temperatures from late-season nests. We show that natural thermal fluctuations have a relatively small effect on developmental variables but enhance hatchling performance and survival at cooler temperatures. Thus, natural thermal fluctuations are important for successful development and simpler approximations (e.g. repeated sine waves, constant temperatures) may poorly reflect natural systems under some conditions. Thus, the benefits of precisely replicating real-world temperatures in controlled studies may outweigh logistical costs. Although patterns might vary according to study system and research goals, our methodological approach demonstrates the importance of incorporating natural variation into controlled studies and provides biologists interested in thermal ecology with a framework for validating the effectiveness of commonly used methods.PublishedYe
Quantification of the Atmospheric Relativistic Electron Precipitation on 17 January 2013
Get PDFOn 17 January 2013, relativistic electron precipitation (REP) was observed on Balloon Array for Radiation Belt Relativistic Electron Losses (BARREL) payloads, National Oceanic and Atmospheric Administration Polar orbiting Operational Environmental Satellites (NOAA POES), and European Space Agency (ESA) MetOp between 2:44 to 15:04 h UT, scattered across dusk to early morning magnetic local time (MLT) sectors. The observations could be grouped into multiple observations of seven REP events spatially separated by more than 2 h in MLT and at least 1 h in UT. Almost all the events were localized in L shell with dL < 0.5 and MLT with dMLT< 3. A net loss of similar to 5% of the relativistic electrons from the radiation belts is estimated between 2:44 to 15:04 h UT (similar to 13.5 h). A majority of atmospheric REP (nearly 75% through six REP events) was observed before the onset of a minor storm around 14:00 UT; the rest (25% through one REP event) was observed during the commencement of the storm which was followed by a major dropout of MeV electrons from the radiation belts during the main phase. However, no atmospheric precipitation was observed during the main phase, indicating that the dropouts may not have been caused by particle loss into the atmosphere.Ye