1,289 research outputs found
Climate Forcing by the Volcanic Eruption of Mount Pinatubo. Revised edition
We determine the volcano climate sensitivity and response time for the Mount
Pinatubo eruption. This is achieved using observational measurements of the
temperature anomalies of the lower troposphere and the aerosol optical density
(AOD) in combination with a radiative forcing proxy for AOD. Using standard
linear response theory we find sensitivity = 0.18 +- 0.04 K/(W/m2), which
implies a negative feedback of -1.0 +- 0.4. The intrinsic response time is
5.8+-1.0 months. Both results are contrary to the conventional paradigm that
includes long response times and positive feedback. In addition, we analyze the
outgoing longwave radiation during the Pinatubo eruption and find that its time
dependence follows the forcing much more closely than the temperature, and even
has an amplitude equal to that of the AOD proxy. This finding is independent of
the response time and feedback results.Comment: 22 pages, including 4 figures. Revised version of a paper [Douglass
D. H. and R. S. Knox (2005), Climate forcing by the volcano eruption of Mount
Pinatubo. Geophys. Res. Lett. 32, L05710.doi: 10.1029/2004GL022119]. Revision
is based on subsequent comments and replies to appear in the same journal.
Quantitative results have only minor change
AGRICULTURAL AND RECREATIONAL IMPACTS FROM SURFACE FLOW CHANGES DUE TO GOLD MINING OPERATIONS
Nevada ranks third in the world in gold production. In order to operate the massive open pit gold mines, the State of Nevada granted mining companies a temporary permit to pump groundwater from near the open pits and dispose of it. Certain instream flows have nearly doubled relative to average historical flows in recent years. Following pit closure, surface flows will likely decline from historical levels. This study measures the impacts of these changing water supplies on downstream agricultural and recreational users. We argue that the creation of temporary changes in water rights for the downstream users would likely mitigate future losses both groups are expected to experience.Resource /Energy Economics and Policy,
Reviews
John Bowden and Ference Marton, The University of Learning: Beyond Quality and Competence in Higher Education, London: Kogan Page, 1998. ISBN: 0–7494–2292–0. Hardback, x310 pages, £35.00
Altitude dependence of atmospheric temperature trends: Climate models versus observation
As a consequence of greenhouse forcing, all state of the art general
circulation models predict a positive temperature trend that is greater for the
troposphere than the surface. This predicted positive trend increases in value
with altitude until it reaches a maximum ratio with respect to the surface of
as much as 1.5 to 2.0 at about 200 to 400 hPa. However, the temperature trends
from several independent observational data sets show decreasing as well as
mostly negative values. This disparity indicates that the three models examined
here fail to account for the effects of greenhouse forcings.Comment: 9 pages, 3 figure
Science, Technology, and Catholic Identity in the Education of Professionals
The reception of Ex corde ecclesiae has been uneven across the disciplines, with scant interest in distinctly Catholic pedagogies outside of the humanities. This essay argues that Catholic universities can distinguish themselves by how they present science and technology in their curriculum by drawing from the interdisciplinary field of “science, technology & society,” or STS. We argue that discussions about Catholic identity, science, and human values can and should extend into the curriculum while simultaneously safeguarding academic freedom, and that this can readily be done in professional schools, such as law and engineering. We outline the contributions that STS as a field could offer Catholic higher education. We discuss how teaching science and technologies as social forces can provide the intellectual and reflective space necessary for critical reflection on their moral dimensions, in society and in the emerging professional lives of students. We argue that STS can help Catholic universities express the Catholic tradition of linking knowledge and wisdom, and thus has the potential to advance the distinctly Catholic character of universities. To substantiate our claims, we present three examples of STS in Catholic higher education curriculum: undergraduate core curriculum, law school instruction, and frugal innovation in engineering education
Integrating Hands-On Undergraduate Research in an Applied Spatial Science Senior Level Capstone Course
A senior within a spatial science Ecological Planning capstone course designed an undergraduate research project to increase his spatial science expertise and to assess the hands-on instruction methodology employed within the Bachelor of Science in Spatial Science program at Stephen F Austin State University. The height of 30 building features estimated remotely with LiDAR data, within the Pictometry remotely sensed web-based interface, and in situ with a laser rangefinder were compared to actual building feature height measurements. A comparison of estimated height with actual height indicated that all three estimation techniques tested were unbiased estimators of height. An ANOVA, conducted on the absolute height errors resulting in a p-value of 0.035, concluded the three height estimating techniques were statistically different at the 95% confidence interval. A Tukey pair-wise test found the remotely sensed Pictometry web-based interface was statistically more accurate than LiDAR data, while the laser range finder was not different from the others. The results indicate that height estimates within the Pictometry web-based interface could be used in lieu of time consuming and costly in situ height measurements. The findings also validate the interactive hands-on instruction methodology employed by Geographic Information Systems faculty within the Arthur Temple College of Forestry and Agriculture in producing spatial science graduates capable of utilizing spatial science technology to accurately quantify, qualify, map, and monitor natural resources
Impact of stratospheric aircraft on calculations of nitric acid trihydrate cloud surface area densities using NMC temperatures and 2D model constituent distributions
A parameterization of NAT (nitric acid trihydrate) clouds is developed for use in 2D models of the stratosphere. The parameterization uses model distributions of HNO3 and H2O to determine critical temperatures for NAT formation as a function of latitude and pressure. National Meteorological Center temperature fields are then used to determine monthly temperature frequency distributions, also as a function of latitude and pressure. The fractions of these distributions which fall below the critical temperatures for NAT formation are then used to determine the NAT cloud surface area density for each location in the model grid. By specifying heterogeneous reaction rates as functions of the surface area density, it is then possible to assess the effects of the NAT clouds on model constituent distributions. We also consider the increase in the NAT cloud formation in the presence of a fleet of stratospheric aircraft. The stratospheric aircraft NO(x) and H2O perturbations result in increased HNO3 as well as H2O. This increases the probability of NAT formation substantially, especially if it is assumed that the aircraft perturbations are confined to a corridor region
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