WATER ALLOCATION IN A CHANGING CLIMATE: INSTITUTIONS AND ADAPTATION

Global warming may profoundly affect temporal and spatial distributions of surface water availability. While climate modelers cannot yet predict regional hydrologic changes with confidence, it is appropriate to begin examining the likely effects of water allocation institutions on society's adaptability to prospective climate change. Such institutions include basic systems of water law, specific statutes, systems of administration and enforcement, and social norms regarding acceptable water-use practices. Both climate and the changing nature of demands on the resource have affected the development and evolution of water allocation institutions in the United States. Water laws and administrative arrangements, for example, have adapted to changing circumstances, but the process of adaptation can be costly and subject to conflict. Analysis of past and ongoing institutional change is used to identify factors that may have a bearing on the costliness of adaptation to the uncertain impacts of global warming on water availability and water demands. Several elements are identified that should be incorporated in the design of future water policies to reduce the potential for disputes and resource degradation that might otherwise result if climate change alters regional hydrology.     

The influence of sampling design on spatial data quality in a geographic citizen science project

Geographic citizen science has much potential to assist in wildlife research and conservation, but the quality of observation data is a key concern. We examined the effects of sampling design on the quality of spatial data collected for a koala citizen science project in Australia. Data were collected from three samples—volunteers (n = 454), an Internet panel (n = 103), and landowners (n = 35)—to assess spatial data quality, a dimension of citizen science projects rarely considered. The locational accuracy of koala observations among the samples was similar when benchmarked against authoritative data (i.e., an expert‐derived koala distribution model), but there were differences in the quantity of data generated. Fewer koala location data were generated per participant by the Internet panel sample than the volunteer or landowner samples. Spatial preferences for land uses affecting koala conservation were also mapped, with landowners more likely to map locations for residential and tourism development and volunteers less likely. These spatial preferences have the potential to influence the social acceptability of future koala conservation proposals. With careful sampling design, both citizen observations and land use preferences can be included within the same project to augment scientific assessments and identify conservation opportunities and constraints.     

Petroleum NAPL Depletion Estimates and Selection of Marker Constituents from Compositional Analysis

Spills and releases of hydrocarbons may result in zones of nonaqueous phase liquids (NAPL) within soils and groundwater. The NAPL will change, or “weather” over time due to a range of physical, chemical, and biological processes. Hydrocarbon constituents in environmental samples collected from NAPL-impacted groundwater wells, sediments, or soils vary in composition over time due to weathering. The changing composition can be used to estimate mass depletion rates and trends for the bulk NAPL and for individual constituent chemicals relative to marker constituents which are less susceptible to weathering. Methods for the selection of marker constituents and for quantitatively and conservatively estimating NAPL depletion rates and trends over time are shown. Estimates are included for two sites with different NAPL mixtures present (crude oil and gasoline/diesel-range product), for which depletion of half the initial total NAPL is estimated at 13.6 ± 2.9 years and 7.3 ± 1.8 years respectively, and with no active NAPL remediation at either site. Similar methods for oil or NAPL depletion estimates have often relied on a prior-identified suite of presumed-conserved marker constituents. The method presented here includes steps which identify the best set of analyzed candidate marker constituents in a NAPL mixture. This can confirm prior-selected markers but is particularly useful for NAPL mixtures in which no prior-identified marker constituents are present.     

Relic permafrost structures in the Gobi of Mongolia: age and significance

Relict permafrost structures (ice-wedge casts and cryoturbation structures) are present in the Gobi of southern Mongolia. Luminescence dates of sediments are presented to constrain the age of formation of permafrost structures. These data show that there was a phase of permafrost development during the latter part of the Last Glacial (after about 22 to 15 ka) that resulted in cryoturbated sediments and ice-wedge casts. Furthermore, permafrost degradation occurred during late Pleistocene times (13–10 ka) and was absent during the early Holocene. These permafrost structures mark the southernmost evidence of permafrost in northern Asia during late Quaternary times and indicate that the mean annual air temperature was below approximately −6°C during their formation. © 1998 John Wiley & Sons, Ltd.     

A paleolimnological record of anthropogenic disturbances at Holmes Lake,Adirondack Mountains,New York

Holmes Lake, Adirondack Mountains, New York, is a clear-water acidic lake that was treated with lime in 1983 to permit stocking of trout. Diatom assemblages in dated sediments reflect three anthropogenic modifications of the lake ecosystem: 1) assemblages from the mid- and late 1800's are associated with historical and sedimentary records of forest clearance, and indicate slightly increased pH; 2) acidobiontic species increase in sediments from the mid-1900's, a period of local reforestation and regionally increasing anthropogenic acid loading; 3) liming caused large increases of circumneutral periphytic species in the first growing season, and decreases of acidobiontic species by the second.     

North Island hill country farmers' management response to issues of sustainability

Abstract:  This paper explores the impediments to optimizing the economic and environmental performance of agriculture in the North Island hill country. The work draws on a range of data sources including consolidated statistical data obtained from The New Zealand Meat and Wool Board's Economic Service (NZMWB) for all North Island hill and hard country farms for the period 1976–77 to 1996–97 and interviews in June and July 1999 with 35 farm households throughout the North Island. Despite generally low levels of profitability, there is considerable evidence that New Zealand farmers have engaged in moves to sustainability to a significant extent.     

The spectrum of RR Telescopii in 1968

The nova-like variable RR Telescopii observed at Cerro Tololo Observatory in 1968 displayed an unusually rich emission line spectrum ranging in excitation from Mgi to [Feviii]. A list of lines with their suggested identifications and approximate intensities covers the range from 3100 to 6700. Only a semi-quantitative discussion is possible since photographic measurements of line intensities could not be calibrated photoelectrically.The spectrum can be interpreted as coming from a highly, inhomogeneous stratified shell illuminated by an extremely hot source. Radiation of Mgi [Oi], [Nii], and [Sii] arises from dense pockets shielded from ionizing radiation. The [Oiii] and [Neiv] radiation appears to originate in strata with densities of the order of 5×10⁶ ions/cm³ and a temperature of the order of 18000 K. The abundance of iron appears to be comparable with that of neon. The helium/hydrogen ratio may be about 0.24.     

The Effect of Wind-Turbine Wakes on Summertime US Midwest Atmospheric Wind Profiles as Observed with Ground-Based Doppler Lidar

We examine the influence of a modern multi-megawatt wind turbine on wind and turbulence profiles three rotor diameters ( $D$ D ) downwind of the turbine. Light detection and ranging (lidar) wind-profile observations were collected during summer 2011 in an operating wind farm in central Iowa at 20-m vertical intervals from 40 to 220 m above the surface. After a calibration period during which two lidars were operated next to each other, one lidar was located approximately $2D$ 2 D directly south of a wind turbine; the other lidar was moved approximately $3D$ 3 D north of the same wind turbine. Data from the two lidars during southerly flow conditions enabled the simultaneous capture of inflow and wake conditions. The inflow wind and turbulence profiles exhibit strong variability with atmospheric stability: daytime profiles are well-mixed with little shear and strong turbulence, while nighttime profiles exhibit minimal turbulence and considerable shear across the rotor disk region and above. Consistent with the observations available from other studies and with wind-tunnel and large-eddy simulation studies, measurable reductions in wake wind-speeds occur at heights spanning the wind turbine rotor (43–117 m), and turbulent quantities increase in the wake. In generalizing these results as a function of inflow wind speed, we find the wind-speed deficit in the wake is largest at hub height or just above, and the maximum deficit occurs when wind speeds are below the rated speed for the turbine. Similarly, the maximum enhancement of turbulence kinetic energy and turbulence intensity occurs at hub height, although observations at the top of the rotor disk do not allow assessment of turbulence in that region. The wind shear below turbine hub height (quantified here with the power-law coefficient) is found to be a useful parameter to identify whether a downwind lidar observes turbine wake or free-flow conditions. These field observations provide data for validating turbine-wake models and wind-tunnel observations, and for guiding assessments of the impacts of wakes on surface turbulent fluxes or surface temperatures downwind of turbines.     

Analysis of selected Kepler Mission planetary light curves

We have modified the graphical user interfaced close binary system analysis program CurveFit to the form WinKepler and applied it to 16 representative planetary candidate light curves found in the NASA Exoplanet Archive (NEA) at the Caltech website http://exoplanetarchive.ipac.caltech.edu, with an aim to compare different analytical approaches. WinKepler has parameter options for a realistic physical model, including gravity-brightening and structural parameters derived from the relevant Radau equation. We tested our best-fitting parameter-sets for formal determinacy and adequacy. A primary aim is to compare our parameters with those listed in the NEA. Although there are trends of agreement, small differences in the main parameter values are found in some cases, and there may be some relative bias towards a 90^° value for the NEA inclinations. These are assessed against realistic error estimates. Photometric variability from causes other than planetary transits affects at least 6 of the data-sets studied; with small pulsational behaviour found in 3 of those. For the false positive KOI 4.01, we found that the eclipses could be modelled by a faint background classical Algol as effectively as by a transiting exoplanet. Our empirical checks of limb-darkening, in the cases of KOI 1.01 and 12.01, revealed that the assigned stellar temperatures are probably incorrect. For KOI 13.01, our empirical mass-ratio differs by about 7 % from that of Mislis and Hodgkin (Mon. Not. R. Astron. Soc. 422:1512, 2012), who neglected structural effects and higher order terms in the tidal distortion. Such detailed parameter evaluation, additional to the usual main geometric ones, provides an additional objective for this work.     

Recent observations of high-degree solar p-mode oscillations at the Kitt Peak National Observatory

A brief summary is given of a program which is currently being carried out with the McMath telescope of the Kitt Peak National Observatory in order to study high-degree (l ≳ 150) solar p-mode oscillations. This program uses a 244 × 248 pixel CID camera and the main spectrograph of the McMath telescope to obtain velocity-time maps of the oscillations which can be converted into two-dimensional (k _h - ω) power spectra of the oscillations. Several different regions of the solar spectrum have been used in order to study the oscillations at different elevations in the solar atmosphere. The program concentrates on eastward- and westward-propagating sectoral harmonic waves so that measurements can be made of the absolute rotational velocities of the solar photospheric and shallow sub-photospheric layers. Some preliminary results from this program are now available. First, we have been unable to confirm the existence of a radial gradient in the equatorial rotational velocity as was previously suggested. Second, we have indeed been able to confirm the presence of p-mode waves in the solar chromosphere as was first suggested by Rhodes et al. (1977). Third, we have been able to demonstrate differences in photospheric and chromospheric power spectra.