Psychological Climate and Work Attitudes: The Importance of Telling the Right Story

In this field study, the authors explore how choosing one context over another influences both research results and implications. Using both quantitative and qualitative data, the authors examine context from both an organizational and a business-unit perspective by studying relationships between five psychological climate variables and outcomes of job satisfaction, affective commitment, and intent to leave. Results show different contextual influences between the organization and two business units, suggesting that different bundles of psychological climate variables yield similar outcomes depending on the context studied. These results bolster the contention that researchers need to identify the right context in field research

New measurements of cosmic infrared background fluctuations from early epochs

Cosmic infrared background fluctuations may contain measurable contribution from objects inaccessible to current telescopic studies, such as the first stars and other luminous objects in the first Gyr of the Universe's evolution. In an attempt to uncover this contribution we have analyzed the GOODS data obtained with the Spitzer IRAC instrument, which are deeper and cover larger scales than the Spitzer data we have previously analyzed. Here we report these new measurements of the cosmic infrared background (CIB) fluctuations remaining after removing cosmic sources to fainter levels than before. The remaining anisotropies on scales > 0.5 arcmin have a significant clustering component with a low shot-noise contribution. We show that these fluctuations cannot be accounted for by instrumental effects, nor by the Solar system and Galactic foreground emissions and must arise from extragalactic sources.Comment: Ap.J.Letters, in pres

Lyman-tomography of cosmic infrared background fluctuations with Euclid: probing emissions and baryonic acoustic oscillations at z>10

The Euclid space mission, designed to probe evolution of the Dark Energy, will map a large area of the sky at three adjacent near-IR filters, Y, J and H. This coverage will also enable mapping source-subtracted cosmic infrared background (CIB) fluctuations with unprecedented accuracy on sub-degree angular scales. Here we propose methodology, using the Lyman-break tomography applied to the Euclid-based CIB maps, to accurately isolate the history of CIB emissions as a function of redshift from 10 < z < 20, and to identify the baryonic acoustic oscillations (BAOs) at those epochs. To identify the BAO signature, we would assemble individual CIB maps over conservatively large contiguous areas of >~ 400 sq deg. The method can isolate the CIB spatial spectrum by z to sub-percent statistical accuracy. We illustrate this with a specific model of CIB production at high z normalized to reproduce the measured Spitzer-based CIB fluctuation. We show that even if the latter contain only a small component from high-z sources, the amplitude of that component can be accurately isolated with the methodology proposed here and the BAO signatures at z>~ 10 are recovered well from the CIB fluctuation spatial spectrum. Probing the BAO at those redshifts will be an important test of the underlying cosmological paradigm, and would narrow the overall uncertainties on the evolution of cosmological parameters, including the Dark Energy. Similar methodology is applicable to the planned WFIRST mission, where we show that a possible fourth near-IR channel at > 2 micron would be beneficial.Comment: comments welcom

Cosmic Infrared Background Fluctuations and Zodiacal Light

We have performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution, or from IRAC observations of high latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS field, at low ecliptic latitude where the zodiacal light intensity varies by factors of $\sim2$ over the range of solar elongations at which the field can be observed. We find that the white noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales ($\gtrsim100"$) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large scale power in the infrared background is not being caused by the zodiacal light.Comment: 17 pp. Accepted for publication in the Ap

Volume Changes Of Alaska Glaciers: Contributions To Rising Sea Level And Links To Changing Climate

Thesis (Ph.D.) University of Alaska Fairbanks, 2006We have used airborne altimetry to measure surface elevations along the central flowline of 86 glaciers in Alaska, Yukon Territory and northwestern British Columbia (northwestern North America). Comparison of these elevations with contours on maps derived from 1950s to 1970s aerial photography yields elevation and volume changes over a 30 to 45 year period. Approximately one-third of glaciers have been re-profiled 3 to 5 years after the earlier profile, providing a measure of short-timescale elevation and volume changes for comparison with the earlier period. We have used these measurements to estimate the total contribution of glaciers in northwestern North America to rising sea level, and to quantify the magnitude of climate changes in these regions. We found that glaciers in northwestern North America have contributed to about 10% of the rate of global sea level rise during the last half-century and that the rate of mass loss has approximately doubled during the past decade. During this time, summer and winter air temperatures at low elevation climate stations increased by 0.2+/-0.1 and 0.4+/-0.2�C (decade)-1 respectively. There was also a weak trend of increasing precipitation and an overall lengthening of the summer melt season. We modeled regional changes in glacier mass balance with climate station data and were able to reproduce altimetry measurements to within reported errors. We conclude that summer temperature increases have been the main driver of the increased rates of glacier mass loss, but winter warming might also be affecting the glaciers through enhanced melt at low elevations and a change in precipitation from snow to rain, especially in maritime regions. Uncertainties in our calculations are large, owing to the inaccuracies of the maps used to provide baseline elevations, the sparsity of accurate climate data, and the complex and dynamic nature of glaciers in these regions. Tidewater, surging, and lake-terminating glaciers have dynamical cycles that are not linked in a simple way to climate variability. We found that regional volume losses can depend on one or several large and dynamic glaciers. These glaciers should be treated separately when extrapolating altimetry data to an entire region