15,521 research outputs found
The October 27-28, 1986, FIRE cirrus case study: Cloud microstructure
Using aircraft in-situ measurements, the microphysics of cirrus clouds observed on 28 Oct. 1986 during FIRE were examined. Results are presented as one component of a coordinated study of the cirrus on the day. The study contributes to the understanding of cold clouds by: (1) providing microphysical data to supplement satellite and aircraft data for investigating cirrus cloud radiative effects; (2) providing more complete information on ice particle evolution and cloud forcing mechanisms than has been available through the use of instrumentation with higher resolution and more accurate calibration; (3) expanding the knowledge of the particle characteristics in cold liquid water clouds, through improved instrumentation and by making use of sensors on other platforms, such as lidar; and (4) by estimating the ice nucleus concentrations active at low temperatures in the upper troposphere from the concentrations of ice particles in colloidally stable liquid water clouds
The impacts of urbanisation and climate change on urban flooding and urban water quality: a review of the evidence concerning the United Kingdom
Study region: United Kingdom (UK). Study focus: Climate change and urbanization pose significant threats for flooding and water
quality in urban areas. This paper reviews the evidence concerning the combined impacts of
urbanisation and climate on the urban water environment of inland catchments of the United
Kingdom and assesses the degree of confidence in reported directions of change and response. It
also assesses the utility of the evidence for setting environmental legislation and managing the
urban water environment in the future and identifies knowledge gaps that limit effective and
management interventions. New hydrological insights: There is a lack of nationally research focused on the dual impacts of
climate change and urbanisation on flooding and water quality in UK urban areas. This is despite
there being a clear acceptance that flood risk is increasing, water quality is generally not meeting
desirable levels, and that combined population and climate change projections pose a pressing
challenge. The available evidence has been found to be of medium-high confidence that both
pressures will result in (i) an increase in pluvial and fluvial flood risk, and (ii) further reduction in
water quality caused by point source pollution and altered flow regimes. Evidence concerning
urban groundwater flooding, diffuse pollution and water temperature was found to be more
sparse and was ascribed a low-medium confidence that both pressures will further exacerbate
existing issues. The confidence ascribed to evidence was also found to reflect the utility of current
science for setting policy and urban planning. Recurring factors that limit the utility of evidence
for managing the urban environment includes: (i) climate change projection uncertainty and
suitability, (ii) lack of sub-daily projections for storm rainfall, (iii) the complexity of managing
and modelling the urban environment, and (iv) lack of probable national-scale future urban landuse
projections. Suitable climate products are increasingly being developed and their application
in applied urban research is critical in the wake of a series of extreme flooding events across the
UK and timely for providing state-of-the-art evidence on which to base possible future water
quality legislation in a post Brexit-WFD era
An AGI with Time-Inconsistent Preferences
This paper reveals a trap for artificial general intelligence (AGI) theorists
who use economists' standard method of discounting. This trap is implicitly and
falsely assuming that a rational AGI would have time-consistent preferences. An
agent with time-inconsistent preferences knows that its future self will
disagree with its current self concerning intertemporal decision making. Such
an agent cannot automatically trust its future self to carry out plans that its
current self considers optimal
Method for the location of burst-onset spectra in the auditory-perceptual space: A study of place of articulation in voiceless stop consonants
This is the publisher's version, also available electronically from http://scitation.aip.org/content/asa/journal/jasa/89/2/10.1121/1.1894648.A method for distinguishing burst onsets of voiceless stop consonants in terms of place of articulation is described. Four speakers produced the voiceless stops in word‐initial position in six vowel contexts. A metric was devised to extract the characteristic burst‐friction components at burst onset. The burst‐friction components, derived from the metric as sensory formants, were then transformed into log frequency ratios and plotted as points in an auditory‐perceptual space (APS). In the APS, each place of articulation was seen to be associated with a distinct region, or target zone. The metric was then applied to a test set of words with voiceless stops preceding ten different vowel contexts as produced by eight new speakers. The present method of analyzing voiceless stops in English enabled us to distinguish place of articulation in these new stimuli with 70% accuracy
Species assemblages of leptocephali in the Subtropical Convergence Zone of the Sargasso Sea
Species assemblages of leptocephali are described in relation to density in the Subtropical Convergence Zone (STCZ) of the Sargasso Sea. Seven transects across fronts were made during four cruises in the late winter or early spring of 1983, 1985 and 1989. About 50 species from 13 families of eels were collected at 66 stations, but fewer than 10 species were abundant in all transects. Four oceanic species, two Anguilla species and Conger oceanicus appeared to be spawning in the STCZ. Leptocephali of most species whose adults inhabit the continental shelf were consistently large in size and were more abundant at or south of fronts and in the western transects. Leptocephali of the two most common oceanic species, Nemichthys scolopaceus and Serrivomer beanii, and the most common shelf species, Ariosoma balearicum, were also more abundant in the western transects, but were abundant at some stations on both sides of fronts. Discontinuities in the assemblages of Anguilla and most shelf species occurred at the location of fronts that formed at the northernmost extent of southern Sargasso Sea surface water (defined as sigma-t \u3c 25.6 kg m−3). These species were rare or absent in mixed convergence zone water (defined as sigma-t 25.2–25.6) north of the fronts. Cluster analysis and ordination of assemblages at 31 night stations reflected the greater species richness and abundance in the west and in the southern water mass. Patterns of assemblage structure within and among transects suggest that convergence of surface water toward fronts in the STCZ may concentrate leptocephali close to fronts and that frontal jets may transport leptocephali eastward
- …