University of New Hampshire

About: University of New Hampshire is a education organization based out in Durham, New Hampshire, United States. It is known for research contribution in the topics: Population & Solar wind. The organization has 9379 authors who have published 24025 publications receiving 1020112 citations. The organization is also known as: UNH.

Evidence of NOx production within or upon ice particles in the Greenland snowpack

Abstract: NOx and NOy were determined in the interstitial air of surface snow and in ambient air at Summit, Greenland. NOx levels in interstitial air were 3 to >10 times those in ambient air, and were generally greater than ambient NOy levels. [NOy] in interstitial air varied diurnally in a manner consistent with photochemical generation within the snowpack. These observations imply that photochemical reactions occurring within or upon the ice crystals of surface snow produced NOx from a N-reservoir compound within the snow. Average [NOx]:[HNO3] and [NOx]:[NOy] ratios in ambient air above the snow were elevated relative to other remote sites, indicating that NOx release within the snowpack may have altered NOx levels in the overlying atmospheric boundary layer. We suggest that the observed release of NOx may have been initiated by photolysis of nitrate, present in relative abundance in surface snow at Summit. Such a process may affect levels of nitrate and other compounds in surface snow, the overlying atmosphere, and glacial ice, and its potential role in cirrus cloud chemistry should be investigated.

Regional variation in foliar chemistry and n cycling among forests of diverse history and composition

Abstract: Although understanding of nitrogen cycling and nitrification in forest ecosystems has improved greatly over the past several decades, our ability to characterize spatial patterns is still quite limited. A number of studies have shown linkages between canopy chemistry and N cycling, but few have considered the degree to which these trends can provide an indicator of forest N status across large, heterogeneous landscapes. In this study, we examined relationships among canopy chemistry, nitrogen cycling, and soil carbon:nitrogen ratios across 30 forested stands in the White Mountains of New Hampshire. Plots included a range of species (sugar maple, red maple, American beech, yellow birch, paper birch, red spruce, balsam fir, eastern hemlock) and were broadly grouped into two disturbance categories: those that were historically affected by intensive logging and/or fire and those that experienced minimal human disturbance. Across all plots, rates of net N mineralization and net nitrification were correlated wi...

A 1400-year high-resolution record of atmospheric circulation over the North Atlantic and Asia:

Abstract: Major ion series developed from new subannual scale sampling of an ice core from central Greenland are calibrated with instrumental series of atmospheric sea-level pressure recording major marine (Icelandic Low) and terrestrial (Siberian High) atmospheric circulation systems to provide proxy records of atmospheric circulation over the past 1400 years. Examination of the proxy records reveals: major changes in behaviour of these systems c. ad 1400, multidecadal- and centennial-scale periodic components, characterization of mean sea-level pressure anomaly fields during the ‘Little Ice Age’ and the ‘Mediaeval Warm Period’, the potential role of solar forcing, coupled ocean-atmosphere associations, and a perspective within which the characteristics of instrumental-era climate can be assessed.

Discipline and deviance: Physical punishment of children and violence and other crime in adulthood

Abstract: This paper presents a theoretical model of the antecedents and consequences of the use of physical punishment by parents and teachers and preliminary tests of that theory using data from a variety of sources, most notably the 3,300 children and 6,000 couples in the National Family Violence Survey. Over 90 percent of American parents use physical punishment to correct misbehavior. The findings support the theory that although physical punishment may produce conformity in the immediate situation, in the longer run it tends to increase the probability of deviance, including delinquency in adolescence and violent crime inside and outside the family as an adult. However, since the findings are based on cross sectional studies, experimental studies are needed to test the causal nature of the relationships. If the results of such experiments support the theory, important implications emerge for both individual parents and national policy. For individual parents, the theory suggests that parents who use no physical punishment will, on the average, have better behaved children. At the national policy level, the theory suggests that one of the steps needed to achieve a society with a minimum of crime and violence is for parents to avoid all use of physical punishment.

The regional and global significance of nitrogen removal in lakes and reservoirs

Abstract: Human activities have greatly increased the transport of biologically available nitrogen (N) through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N year−1 from watersheds globally. Small lakes (<50 km2) were critical in the analysis, retaining almost half (9.3 Tg N year−1) of the global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially at the half-degree scale (0–100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain ~33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area:lake or reservoir surface area), higher apparent settling velocities for N, and greater average N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale.