The work intensity function in the detection of greenhouse induced global temperature trends

Summary A work intensity function is defined as the product of the frequencies exhibited by a column in a histogram and the magnitude of the midpoint of the class interval of the column. An intensity distribution is defined as the cumulative sum of the function along the abscissa. These functions are examined first for a normal distribution, and then for the expected deviations shown by a sample assumed to be drawn from a normal distribution. The theoretical maximum of the intensity is found at one standard deviation for the normal distribution and at 2 s.d. (standard deviation) for a sample drawn from a normal distribution. The cumulative sum of the intensity is more biased towards outlying values of larger magnitude for the sample than for the normal distribution. 10% of the cumulative sum of the intensities is generated at s.d. greater than 3 for the sample compared to only 1% for the normal distribution itself. These statistics are compared with similar ones computed for the Jones-Parker (1991) series of mean global surface temperature anomaly interannual differences. The agreement between theory and the data series is good. The data series appears to possess those properties which would be expected of it if the series was a sample drawn from a normal distribution. It is concluded that the work intensity and its cumulative sum are useful tools in diagnosing the behaviour of a population of anomaly values. These statistics do not clarify the problem of identifying a greenhouse gas induced global warming but they do suggest that its identification continues to be as difficult as ever, due to the effect of occasional outlying values.With 2 Figures     

Petrogenesis of Variscan high-temperature Group A eclogites from the Moldanubian Zone of the Bohemian Massif,Czechoslovakia

High-temperature (HT), Group A eclogites from three localities in the Moldanubian Zone of the Bohemian Massif are interpreted to have formed in the mantle and to have been transported into the crust by their enclosing garnet peridotites during Variscan orogenesis. Garnet and omphacite are compositionally zoned and contain homogeneous cores and retrograde rims. Cores of minerals yield minimum temperatures and pressures of 850 to 985°C and 16.0 to 22.5 kb, based on Fe–Mg exchange between garnet and clinopyroxene and the jadeite content of clinopyroxene. Sugh high temperatures indicate equilibration in, and derivation from, the upper mantle. Trace element compositions, including the REEs, high MgO contents, and high Mg numbers suggest that the rocks formed by high pressure accumulation of garnet and clinopyroxene and variable amounts of trapped melt. Sm-Nd ages determined on four garnet-clinopyroxene pairs from the three localities are 377±20, 342±9, 336±16, and 323±7 Ma. _Nd and initial ⁸⁷Sr/⁸⁶Sr are negatively correlated, varying from +6.7 to -0.1 and 0.7027 to 0.7057, respectively. Field, compositional, and isotopic data indicate that the eclogites were derived from heterogeneous mantle that included depleted and enriched compositions; this heterogeneity may have resulted from subduction processes that occurred prior to the late Variscan collision of Gondwana and Baltica.     

On the hard X-ray spatial structure during the impulsive phase of solar flares

Using a simplified form of the bremsstrahlung cross-section, we obtain an analytic expression for the intensity of electron-beam-produced hard X-ray emission with depth in solar flares. The results show that footpoint emission is more likely than previously thought, and we discuss these results in the light of recent observations.Presidential Young Investigator.NAS/NRC Research Associate, on leave from CNIE, San Miguel, Argentina.     

Ethnic diversity,scarcity and drinking water: a provocation to rethink provisioning metropolitan mains water

Urban water scarcity in south-east Australia forces us to engage with how our present centralised public utilities are embedded in our everyday lives, amidst uncertain futures. In the last decades, socio-technical approaches have illustrated how the myth of endless main water supply is made possible by cultures of engineering and plumbing. To extend debates about the cultural dimensions of environmental sustainability, this paper takes an ethnographic approach to understand the processes by which Burmese refugees and migrants who lived with water scarcity pre-migration make water potable post-migration to Australia. With a focus on mapping the material, discursive, spatial and emotional relations that enable the provisioning of potable water, the paper brings into conversation Elizabeth Shove's social practice theory with Elspeth Probyn's emplaced formulation of subjectivity. The adaptive provisioning capacities of people whose lives are immersed in cultures of water scarcity point towards a politics and relational ethics of care underpinned by provisioning and first-person contact. To conclude, these grounded Burmese examples provide an opportunity to employ scenario thinking to imagine alternative drinking water futures for south-east Australian cities.     

Pressure–temperature–structural distance relationships within Greater Himalayan rocks in eastern Bhutan: implications for emplacement models

In the Himalayan orogen, Greater Himalayan (GH) rocks were buried to mid‐ to lower‐crustal levels and are now exposed across the strike of the orogen. Within the eastern Himalaya, in the Kingdom of Bhutan, the GH is divided into structurally lower (lower‐GH) and upper (upper‐GH) levels by the Kakhtang thrust (KT). Pressure–temperature estimates from lower‐ and upper‐GH rocks collected on two transects across the KT yield similar P–T–structural distance trends across each transect. In the eastern transect, temperatures are similar (from 730 to 650 °C) over a structural thickness of ~11 km, but peak pressures decrease from ~10 to 6 kbar with increasing structural level. In comparison, peak temperatures in the central Bhutan transect are similar (from 730 to 600 °C), but pressures decrease from 10 to 6.5 kbar with increasing structural level over a structural thickness of ~6 km. The structurally highest sample reveals slightly higher pressures of 8.0 kbar in comparison to pressures of ~6.5 kbar for samples collected from within the KT zone, ~4 km below. Within each transect, there are increases in pressure ± temperature within the overall upright P–T gradient that may demarcate intra‐GH shear zone(s). These P–T results combined with evidence that the timing of initial melt crystallization becomes older with increasing structural level suggest that the intra‐GH shear zones emplaced deeper GH rocks via progressive ductile underplating. These shear zones, including the KT, likely aided in the initial emplacement and construction of the GH as a composite tectonic unit during the Late Oligocene to Early Miocene, from c. 27 to 16 Ma.     

Geology from rail journeys: the Inverness to Wick Line,Scotland

The Inverness to Wick railway line enables travellers to track the geological history of the far northeast of Scotland, spanning about 1000 million years, and starting in the Neoproterozoic. This history includes the Caledonian Orogeny, the deposition of Old Red Sandstone and Mesozoic sediments, the latter along the faulted margins close to the Great Glen Fault system, and ends with Pleistocene and Holocene deposition and erosion.     

Steps for solving the radiative transfer equation for arbitrary flows in stationary space–times

We derive the radiative transfer equation for arbitrary stationary relativistic flows in stationary space–times, i.e. for steady-state transfer problems. We show how the standard characteristics method of solution developed by Mihalas and used throughout the radiative transfer community can be adapted to multidimensional applications with isotropic sources. Because the characteristics always coincide with geodesics and can always be specified by constants, direct integration of the characteristics derived from the transfer equation as commonly done in 1D applications is not required. The characteristics are known for a specified metric from the geodesics. We give details in both flat and static spherically symmetric space–times. This work has direct application in 3D simulations of supernovae, gamma-ray bursts, and active galactic nuclei, as well as in modelling neutron star atmospheres.     

Quantifying groundwater–surface water interactions in a proglacial valley,Cordillera Blanca,Peru

A myriad of downstream communities and industries rely on streams fed by both groundwater discharge and glacier meltwater draining the Cordillera Blanca, Northern Peruvian Andes, which contains the highest density of glaciers in the tropics. During the dry season, approximately half the discharge in the region's proglacial streams comes from groundwater. However, because of the remote and difficult access to the region, there are few field methods that are effective at the reach scale to identify the spatial distribution of groundwater discharge. An energy balance model, Rhodamine WT dye tracing, and high‐definition kite‐borne imagery were used to determine gross and net groundwater inputs to a 4‐km reach of the Quilcay River in Huascaran National Park, Peru. The HFLUX computer programme ( http://hydrology.syr.edu/hflux.html ) was used to simulate the Quilcay River's energy balance using stream temperature observations, meteorological measurements, and kite‐borne areal photography. Inference from the model indicates 29% of stream discharge at the reach outlet was contributed by groundwater discharge over the study section. Rhodamine WT dye tracing results, coupled with the energy balance, show that approximately 49% of stream water is exchanged (no net gain) with the subsurface as gross gains and losses. The results suggest that gross gains from groundwater are largest in a moraine subreach but because of large gross losses, net gains are larger in the meadow subreaches. These insights into pathways of groundwater–surface water interaction can be applied to improve hydrological modelling in proglacial catchments throughout South America. Copyright © 2016 John Wiley & Sons, Ltd.