109 research outputs found
CMBPol Mission Concept Study: A Mission to Map our Origins
Quantum mechanical metric fluctuations during an early inflationary phase of
the universe leave a characteristic imprint in the polarization of the cosmic
microwave background (CMB). The amplitude of this signal depends on the energy
scale at which inflation occurred. Detailed observations by a dedicated
satellite mission (CMBPol) therefore provide information about energy scales as
high as GeV, twelve orders of magnitude greater than the highest
energies accessible to particle accelerators, and probe the earliest moments in
the history of the universe. This summary provides an overview of a set of
studies exploring the scientific payoff of CMBPol in diverse areas of modern
cosmology, such as the physics of inflation, gravitational lensing and cosmic
reionization, as well as foreground science and removal .Comment: 6 pages, 3 figure
From Resistance to Receptiveness: Farmer Willingness to Participate in Extension Discussions About Climate Variability and Climate Change
Identifying what Extension professionals believe are the critical elements of a communication strategy that is most likely to encourage agricultural producers to participate in discussions of climate variability and climate change is pivotal to providing timely solutions to issues facing farmers. The current study involved interviews with 50 Extension professionals from four southeastern states (Alabama, Florida, Georgia, and South Carolina) who were engaged in ongoing work related to climate and agriculture. Respondents were asked to assess how best to engage farmers in conversations related to climate variability and climate change. Qualitative analysis showed that Extension professionals recommended avoiding content related to politics, attribution of climate change to human causes, and telling farmers what to do. Respondents recommended emphasizing adaptation strategies, climate variability over climate change, evidence that climate change exists, and the financial benefits for farmers. In addition, Extension professionals proposed several delivery methods they thought would be most effective with farmers, including delivery tailored to the characteristics of the audience, a positive overall tone, and an understanding that engagement should be viewed as a long-term process based on building relationships with farmers. The findings suggest that farmers are a potentially receptive audience on climate issues when properly approached
Profitability, Engaging Delivery, and Trust: How Extension Professionals Can Optimize Farmer Adoption of Climate-related Adaptation Strategies
This study examined Extension professionals’ perspectives on how to optimize the chances that farmers will adopt climate adaptation strategies designed to minimize risks associated with climate variability and climate change. In-depth interviews were conducted with Extension professionals in four southeastern states (Alabama, Florida, Georgia, and South Carolina). Responses were coded and analyzed, resulting in three recommendations. First, focus on profitability and issues of immediate concern to farmers. Second, use engaging delivery methods, especially field trials conducted under realistic conditions. Third, build trust with farmers, primarily by focusing on research-based information. This study has practical implications for how Extension professionals should approach the work of addressing climate issues in agriculture
Climate-Related Risks and Management Issues Facing Agriculture in the Southeast: Interviews with Extension Professionals
To explore Extension professionals\u27 perceptions of the potential impact of climate variability and climate change on agriculture and to identify the top climate-related issues facing farmers, we conducted interviews with agricultural Extension personnel from Alabama, Florida, Georgia, and South Carolina. Of those interviewed, 92% believed climate change will affect agriculture a moderate amount or a great deal. Qualitative analyses revealed that the Extension professionals considered scarcity of water resources, temperature fluctuations, pest and disease pressures, forecast challenges, seasonal variability, and adaptation strategies as among the most important climate-related issues affecting agriculture in the Southeast
Toward Engagement in Climate Training: Findings from Interviews with Agricultural Extension Professionals
With scientific consensus regarding the occurrence of climate variability and climate change it is clear that farmers can benefit from science-based adaptation strategies for managing climate-related risk. To this end, cooperative extension professionals must engage in climate training events that are carefully planned and tailored to their specific needs. This study consisted of 50 interviews with extension professionals from four states (Alabama, Florida, Georgia, and South Carolina) and collected information about the perceptions of climate variability and change as well as the preferred approaches for climate-related training in extension. Results include the need for accessible, climate-related training that prepares extension professionals to: understand both management- and technology-related adaptation strategies, engage in productive conversations with all stakeholders, and participate in the coproduction of knowledge related to climate issues
CMBPol Mission Concept Study: Gravitational Lensing
Gravitational lensing of the cosmic microwave background by large-scale
structure in the late universe is both a source of cosmological information and
a potential contaminant of primordial gravity waves. Because lensing imprints
growth of structure in the late universe on the CMB, measurements of CMB
lensing will constrain parameters to which the CMB would not otherwise be
sensitive, such as neutrino mass.
If the instrumental noise is sufficiently small (<~ 5 uK-arcmin), the
gravitational lensing contribution to the large-scale B-mode will be the
limiting source of contamination when constraining a stochastic background of
gravity waves in the early universe, one of the most exciting prospects for
future CMB polarization experiments. High-sensitivity measurements of
small-scale B-modes can reduce this contamination through a lens reconstruction
technique that separates the lensing and primordial contributions to the B-mode
on large scales.
A fundamental design decision for a future CMB polarization experiment such
as CMBpol is whether to have coarse angular resolution so that only the
large-scale B-mode (and the large-scale E-mode from reionization) is measured,
or high resolution to additionally measure CMB lensing. The purpose of this
white paper is to evaluate the science case for CMB lensing in polarization:
constraints on cosmological parameters, increased sensitivity to the gravity
wave B-mode via lens reconstruction, expected level of contamination from
non-CMB foregrounds, and required control of beam systematics
CMBPol Mission Concept Study: Prospects for polarized foreground removal
In this report we discuss the impact of polarized foregrounds on a future
CMBPol satellite mission. We review our current knowledge of Galactic polarized
emission at microwave frequencies, including synchrotron and thermal dust
emission. We use existing data and our understanding of the physical behavior
of the sources of foreground emission to generate sky templates, and start to
assess how well primordial gravitational wave signals can be separated from
foreground contaminants for a CMBPol mission. At the estimated foreground
minimum of ~100 GHz, the polarized foregrounds are expected to be lower than a
primordial polarization signal with tensor-to-scalar ratio r=0.01, in a small
patch (~1%) of the sky known to have low Galactic emission. Over 75% of the sky
we expect the foreground amplitude to exceed the primordial signal by about a
factor of eight at the foreground minimum and on scales of two degrees. Only on
the largest scales does the polarized foreground amplitude exceed the
primordial signal by a larger factor of about 20. The prospects for detecting
an r=0.01 signal including degree-scale measurements appear promising, with 5
sigma_r ~0.003 forecast from multiple methods. A mission that observes a range
of scales offers better prospects from the foregrounds perspective than one
targeting only the lowest few multipoles. We begin to explore how optimizing
the composition of frequency channels in the focal plane can maximize our
ability to perform component separation, with a range of typically 40 < nu <
300 GHz preferred for ten channels. Foreground cleaning methods are already in
place to tackle a CMBPol mission data set, and further investigation of the
optimization and detectability of the primordial signal will be useful for
mission design.Comment: 42 pages, 14 figures, Foreground Removal Working Group contribution
to the CMBPol Mission Concept Study, v2, matches AIP versio
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
We summarize the utility of precise cosmic microwave background (CMB)
polarization measurements as probes of the physics of inflation. We focus on
the prospects for using CMB measurements to differentiate various inflationary
mechanisms. In particular, a detection of primordial B-mode polarization would
demonstrate that inflation occurred at a very high energy scale, and that the
inflaton traversed a super-Planckian distance in field space. We explain how
such a detection or constraint would illuminate aspects of physics at the
Planck scale. Moreover, CMB measurements can constrain the scale-dependence and
non-Gaussianity of the primordial fluctuations and limit the possibility of a
significant isocurvature contribution. Each such limit provides crucial
information on the underlying inflationary dynamics. Finally, we quantify these
considerations by presenting forecasts for the sensitivities of a future
satellite experiment to the inflationary parameters.Comment: 107 pages, 14 figures, 17 tables; Inflation Working Group
contribution to the CMBPol Mission Concept Study; v2: typos fixed and
references adde
- …