Pseudoeurycea unguidentis

Number of Pages: 2Integrative BiologyGeological Science

Pseudoeurycea longicauda

Number of Pages: 2Integrative BiologyGeological Science

Trends in wintertime climate in the northeastern United States: 1965–2005

Humans experience climate variability and climate change primarily through changes in weather at local and regional scales. One of the most effective means to track these changes is through detailed analysis of meteorological data. In this work, monthly and seasonal trends in recent winter climate of the northeastern United States (NE-US) are documented. Snow cover and snowfall are important components of the region\u27s hydrological systems, ecosystems, infrastructure, travel safety, and winter tourism and recreation. Temperature, snowfall, and snow depth data were collected from the merged United States Historical Climate Network (USHCN) and National Climatic Data Center Cooperative Network (COOP) data set for the months of December through March, 1965–2005. Monthly and seasonal time series of snow-covered days (snow depth \u3e2.54 cm) are constructed from daily snow depth data. Spatial coherence analysis is used to address data quality issues with daily snowfall and snow depth data, and to remove stations with nonclimatic influences from the regional analysis. Monthly and seasonal trends in mean, minimum, and maximum temperature, total snowfall, and snow-covered days are evaluated over the period 1965–2005, a period during which global temperature records and regional indicators exhibit a shift to warmer climate conditions. NE-US regional winter mean, minimum, and maximum temperatures are all increasing at a rate ranging from 0.42° to 0.46°C/decade with the greatest warming in all three variables occurring in the coldest months of winter (January and February). The regional average reduction in number of snow-covered days in winter (−8.9 d/decade) is also greatest during the months of January and February. Further analysis with additional regional climate modeling is required to better investigate the causal link between the increases in temperature and reduction in snow cover during the coldest winter months of January and February. In addition, regionally averaged winter snowfall has decreased by about 4.6 cm/decade, with the greatest decreases in snowfall occurring in December and February. These results have important implications for the impacts of regional climate change on the northeastern United States hydrology, natural ecosystems, and economy

The clustering of radio galaxies at z~0.55 from the 2SLAQ LRG survey

We examine the clustering properties of low-power radio galaxies at redshift 0.4<z<0.8, using data from the 2SLAQ Luminous Red Galaxy (LRG) survey. We find that radio-detected LRGs (with optical luminosities of 3-5L* and 1.4GHz radio powers between 1e24 and 1e26 W/Hz) are significantly more clustered than a matched sample of radio-quiet LRGs with the same distribution in optical luminosity and colour. The measured scale length of the 2pt auto-correlation function, r0, is 12.3+/-1.2 1/h Mpc and 9.02+/-0.52 1/h Mpc for the radio-detected and radio-quiet samples respectively. Using the halo model framework we demonstrate that the radio-loud LRGs have typical halo masses of 10.1+/-1.4 x10^13 1/h M_sun compared to 6.44+/-0.32 x10^13 1/h M_sun for the radio-quiet sample. A model in which the radio-detected LRGs are almost all central galaxies within haloes provides the best fit, and we estimate that at least 30% of LRGs with the same clustering amplitude as the radio-detected LRGs are currently radio-loud. Our results imply that radio-loud LRGs typically occupy more massive haloes than other LRGs of the same optical luminosity, so the probability of finding a radio-loud AGN in a massive galaxy at z~0.55 is influenced by the halo mass in addition to the dependence on optical luminosity. If we model the radio-loud fraction of LRGs, F_rad, as a function of halo mass M, then the data are well-fitted by a power law of the form F_rad \propto M^(0.65+/-0.23). The relationship between radio emission and clustering strength could arise either through a higher fuelling rate of gas onto the central black holes of galaxies in the most massive haloes (producing more powerful radio jets) or through the presence of a denser IGM (providing a more efficient working surface for the jets, thus boosting their radio luminosity).Comment: Accepted for publication in MNRA

The Stripe 82 Massive Galaxy Project III: A Lack of Growth Among Massive Galaxies

The average stellar mass (Mstar) of high-mass galaxies (Mstar > 3e11 Msun) is expected to grow by ~30% since z~1, largely through ongoing mergers that are also invoked to explain the observed increase in galaxy sizes. Direct evidence for the corresponding growth in stellar mass has been elusive, however, in part because the volumes sampled by previous redshift surveys have been too small to yield reliable statistics. In this work, we make use of the Stripe 82 Massive Galaxy Catalog to build a mass-limited sample of 41,770 galaxies (Mstar > 1.6e11) with optical to near-IR photometry and a large fraction (>55%) of spectroscopic redshifts. Our sample spans 139 square degrees, significantly larger than most previous efforts. After accounting for a number of potential systematic errors, including the effects of Mstar scatter, we measure galaxy stellar mass functions over 0.3 < z < 0.65 and detect no growth in the typical Mstar of massive galaxies with an uncertainty of 9%. This confidence level is dominated by uncertainties in the star formation history assumed for Mstar estimates, although our inability to characterize low surface-brightness outskirts may be the most important limitation of our study. Even among these high-mass galaxies, we find evidence for differential evolution when splitting the sample by recent star formation (SF) activity. While low-SF systems appear to become completely passive, we find a mostly sub-dominant population of galaxies with residual, but low rates of star formation (~1 Msun/yr) number density does not evolve. Interestingly, these galaxies become more prominent at higher Mstar, representing ~10% of all galaxies at Mstar ~ 1e12 Msun and perhaps dominating at even larger masses.Comment: Accepted in Ap

Hydrological Investigations at Biafo Glacier, Karakoram Range, Himalaya; an Important Source of Water For the Indus River

Over 80% of the flow of the Upper Indus River is derived from less than 20% of its area: essentially from zones of heavy snowfall and glacierized basins above 3500 m elevation. The trans-Himalaya n contribution comes largely from an area of some 20000 km2 of glacierized basins, mostly along the axis of the Greater Karakoram range and especially from 20-30 of the largest glacier basins. Very few glaciological investigations have so far been undertaken in this the major glacierized region of Central Asia. Biafo Glacier, one of the largest of the Karakoram glaciers, drains south-eastwards from the central Karakoram crest. Its basin covers a total area of 853 km2 , 628 km2 of which are permanent snow and ice, with 68% of the glacier area forming the accumulation zone. This paper describes investigations of snow accumulation, ablation , glacier movement, and glacier depth undertaken in the period 1985-87 , set against a background of investigations carried out over the last 130 yea rs. Biafo Glacier differs from most of the other Karakoram glaciers in being nourished mainly by direct snowfall rather than by avalanching; this has the advantage of allowing extensive investigation of accumulation over a broad range of altitude. Snow-accumulation studies in the Biafo Glacier basin have indicated that annual accumulation varies from 0.9 to 1.9 m of water equivalent between 4650 and 5450 m a .. s.l. This suggests an annual moisture input above the equilibrium line of approximately 0.6 km3. Monopulse radar measurements indicate the presence of ice thickness as great as 1400 m at the equilibrium line, although these results may not be completely reliable . Mean surface velocity during the summer of 0.8 m d -I has been measured near to the equilibrium line. Calculations of annual ice flux through the vertical cross-profile at the equilibrium line indicate a throughput of 0.7 km3 a-I Estimates from stake ablation measurements also suggest that ice loss on Biafo Glacier is about 0.7 km3 a-I. The close agreement between these three sets of measurements is reassuring, indicating that the ablation zone of Biafo Glacier, whose area covers 0.09% of the whole Upper Indus basin, produces approximately 0.9% of the total run-off. However. it should be mentioned that this estimate does not include water originating from seasonal snow melt, e either above or below the equilibrium line, or from rainfall. Net annual ice losses due to wastage of the glacier since 1910 are probably of the order of 0.4-{).5 m a-I; this would represent between 12 and 15% of annual water yield from melting ice

Simultaneous Dual Band Transmission Over Multimode Fiber-Fed Indoor Wireless Network

Performance measurements of different combinations of digital enhanced cordless telecommunications packet radio service, global system for mobile communications, universal mobile telecommunication service, and 802.11g (54 Mbps) signals in a dual band configuration transmitted over an indoor wireless network fed by a low-cost 850-nm vertical-cavity surface-emitting laser (VCSEL)-300m multimode fiber link are presented. The feasibility of such a system is demonstrated with error vector magnitude measurements which are within the required specification