Publications Published in 1997

1. Anaerobic digestion of biomass for methane production: A review. Gunaseelan, V Nallathambi.
   Biomass and Bioenergy: 1997
   Notes
   Biological conversion of biomass to methane has received increasing attention in recent years. Hand- and mechanically-sorted municipal solid waste and nearly 100 genera of fruit and vegetable solid wastes, leaves, grasses, woods, weeds, marine and freshwater biomass have been explored for their anaerobic digestion potential to methane. In this review, the extensive literature data have been tabulated and ranked under various categories and the influence of several parameters on the methane potential of the feedstocks are presented. Almost all the land- and water-based species examined to date either have good digestion characteristics or can be pre-treated to promote digestion. This review emphasizes the urgent need for evaluating the inumerable unexplored genera of plants as potential sources for methane production.
   
   
   
2. ANALYSIS Incentives, precision technology and environmental protection. Khanna, Madhu; Zilberman, David.
   Ecological Economics: 1997
   Notes
   This paper calls for a reevaluation of the pollution problem in order to devise efficient strategies for its control. It contends that a fundamental cause of pollution is inefficiency in input-use during the production process. This inefficiency manifests itself as input-waste and polluting residues. Precision technologies can increase the effectiveness of inputs used in production and reduce pollution generation. Despite their potential economic and ecological benefits, adoption of precision technologies has been slow. This paper presents a conceptual framework to identify and analyze the specific factors that affect their diffusion among microunits. These include various heterogeneous characteristics of microunits, prices which do not reflect the relevant scarcities due to distortionary regulatory policies and lack of institutional mechanisms for efficient allocation of inputs and outputs. It rationalizes the observed variations in the appropriate choice of technology across microunits and argues for the need to broaden the range of incentive-based instruments for environmental protection beyond pollution taxes.
   
   
   
3. A New Assessment of Possible Solar and Lunar Forcing of the Bidecadal Drought Rhythm in the Western United States. Cook, Edward R; Meko, David M; Stockton, Charles W.
   Journal of Climate: 1997
   Notes
   A new drought area index (DAI) for the United States has been developed based on a high-quality network of drought reconstructions from tree rings. This DAI is remarkably similar to one developed earlier based on much less data and shows strong evidence for a persistent bidecadal drought rhythm in the western United States since 1700. This rhythm has in the past been associated with possible forcing by the 22-yr Hale solar magnetic cycle and the 18.6-yr lunar nodal tidal cycle. The authors make a new assessment of these possible forcings on DAI using different methods of analysis. In so doing, they confirm most of the previous findings. In particular, there is a reasonably strong statistical association between the bidecadal drought area rhythm and years of Hale solar cycle minima and 18.6-yr lunar tidal maxima. The authors also show that the putative solar and lunar effects appear to be interacting to modulate the drought area rhythm, especially since 1800. These results do not eliminate the possibility that the drought area rhythm is, in fact, internally forced by coupled ocean–atmosphere processes. Recent modeling results suggest that unstable ocean–atmosphere interactions in the North Pacific could be responsible for the drought rhythm as well. However, the results presented here do not easily allow for the rejection of the solar and lunar forcing hypotheses either.
   
   
   
4. A pacific interdecadal climate oscillation with impacts on salmon production. Mantua, N. J.; Hare, S. R.; Zhang, Y.; Wallace, J. M.; Francis, R. C..
   Bulletin of the American Meteorological Society: 1997
   Notes
   Evidence gleaned from the instrumental record of climate data identifies a robust, recurring pattern of ocean- atmosphere climate variability centered over the midlatitude North Pacific basin. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal timescales. Then is evidence of reversals in the prevailing polarity of the oscillation occurring around 1925, 1947, and 1977; the last two reversals correspond to dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures, as well as streamflow in major west coast river systems, from Alaska to California.
   
   
   
5. Attenuation of methane and nonmethane organic compounds in landfill gas affected soils. Kjeldsen, Peter; Dalager, Anne; Broholm, Kim.
   Journal of the Air & Waste Management Association: 1997
   Notes
   Investigates the degradation of landfill gas (LFG) constituents in LFG-affected soils. Evaluation of the importance of the degradation processes to the emission; Studies on the influence of methane oxidation on the lateral migration of landfill gas.
   
   
   
6. Changes in an Assemblage of Temperate Reef Fishes Associated with a Climate Shift. Sally J. Holbrook; Russell J. Schmitt; John S. Stephens, Jr..
   Ecological Applications: 1997
   Notes
   Substantial changes have occurred in assemblages of near shore reef fishes in the Southern California Bight during the past two decades. At two sites off Los Angeles, California , species richness of reef fishes fell 15-25%, and composition shifted from dominance by northern to southern species. Additionally, by 1993, 95% of the fish species had declined in abundance by an average of 69%. Concurrent declines of similar magnitude were observed for several trophic levels of the benthic ecosystem farther north at Santa Cruz Island where populations of surfperches (Pisces: embiotocidae), the standing stock of their crustacean prey, and the biomass of understory microalgae all declined by ~80%. Abundance of fishes fell because declining recruitment of age-0 fish was insufficient ot compensate for losses of older age classes. Annual levels of recruitment of age-0 fishes at all reefs examined fell more than one order of magnitude over two decades and was correlated among years with a broad indicator of Bight-wide productivity, the biomass of macrozooplankton in the California Current. Lower productivity if the coastal marine ecosystem, associated with a climate regime shift in 1976-1977, likely caused large, but unforeseen, impacts on population abundances and trophic structure in near shore benthic communities.
   
   
   
7. Downscaling general circulation model output: a review of methods and limitations . Wilby, R.L.; Wigley, Tom M. L..
   Progress in Physcial Geography: 1997
   Notes
   General circulation models (GCMs) suggest that rising concentrations of greenhouse gases may have significant consequences for the global climate. What is less clear is the extent to which local (subgrid) scale meteorological processes will be affected. So-called 'downscaling' techniques have subsequently emerged as a means of bridging the gap between what climate modellers are currently able to provide and what impact assessors require. This article reviews the present generation of downscaling tools under four main headings: regression methods; weather pattern (circulation)-based approaches; stochastic weather generators; and limited-area climate models. The penultimate section summarizes the results of an international experiment to intercompare several precipitation models used for downscaling. It shows that circulation-based precipitation characteristics, but are able to capture only part of the daily precipitation variability changes associated with model-derived changes in climate. The final section examines a number of ongoing challenges to the future development of climate downscaling.
   
   
   
8. Effect of rice cultivars and fertilizer management on methane emission in a rice paddy in Beijing. Kesheng, Shao; Li, Zhen.
   Nutrient Cycling in Agroecosystems: 1997
   Notes
   Experiments were conducted during April-Oct. 1994 in a Beijing rice field. Four types of rice varieties have been tested. Large cultivar differences in methane emission flux have been found. Variety 93812 emitted about fivefold more CH4 than did the Qiuguang variety. An organic amendment plus (NH4)2SO4as the base fertilizer and (NH4)2SO4as the topdressing applied in different amounts and growth stages, compared with no topdressing, reduced methane emission about 58% and increased rice yield about 31.7%. Emission peaks of CH4 in the tillering stage and reproductive stage were suppressed. A comprehensive strategy could meet both the goal for sustainable rice productivity and methane reduction. Such a strategy includes: 1. Selection of cultivars which have reduced root exudate and litter but increased root mass most of which growing in the oxidized soil layer, cultivars also need an effective number of tillers for optimum yield but with less CH4transportation ability; 2. Application of organic manure combined with chemical fertilizers, that reduce CH4 emissions. Fertilizers such as SO4 2 -or other inhibitors can be maintained for a long period in soil; 3. Adoption of scientific irrigation mode such as flooding-drainage- intermittent irrigation ,that can both increase the rice yield and decrease the CH4 emission, etc..
   
   
   
9. El nino and climate change. Trenberth, K. E.; Hoar, T. J..
   Geophysical Research Letters: 1997
   Notes
   A comprehensive statistical analysis of how an index of the Southern Oscillation changed from 1882 to 1995 was given by Trenberth and Hoar [1996], with a focus on the unusual nature of the 1990-1995 El Nino-Southern Oscillation (ENSO) warm event in the context of an observed trend for more EI Nino and fewer La Nina events after the late 1970s. The conclusions of that study have been challenged by two studies which deal with only the part of our results pertaining to the length of runs of anomalies of one sign in the Southern Oscillation Index. They therefore neglect the essence of Trenberth and Hear, which focused on the magnitude of anomalies for certain periods and showed that anomalies during both the post-1976 and 1990-mid-1995 periods were highly unlikely given the previous record.
   
   
   
10. Emissions from ships. Corbett, James J; Fischbeck, Paul.
    Science: 1997
    Notes
    Reports on research being done by the International Maritime Organization (IMO) into how much ships contribute to global air pollution. Examination of geographic distribution of ship emissions; Findings; IMO naming the Baltic Sea as the first SOx Emission Control Area; Problems in regulating the amount of air polluting emissions from ships.