Ski areas, weather and climate: Time series models for New England case studies

Wintertime warming trends experienced in recent decades, and predicted to increase in the future, present serious challenges for ski areas and whole regions that depend on winter tourism. Most research on this topic examines past or future climate-change impacts at yearly to decadal resolution, to obtain a perspective on climate-change impacts. We focus instead on local-scale impacts of climate variability, using detailed daily data from two individual ski areas. Our analysis fits ARMAX (autoregressive moving average with exogenous variables) time series models that predict day-to-day variations in skier attendance from a combination of mountain and urban weather, snow cover and cyclical factors. They explain half to two-thirds of the variation in these highly erratic series, with no residual autocorrelation. Substantively, model results confirm the backyard hypothesis that urban snow conditions significantly affect skier activity; quantify these effects alongside those of mountain snow and weather; show that previous-day conditions provide a practical time window; find no monthly effects net of weather; and underline the importance of a handful of high-attendance days in making or breaking the season. Viewed in the larger context of climate change, our findings suggest caution regarding the efficacy of artificial snowmaking as an adaptive strategy, and of smoothed yearly summaries to characterize the timing-sensitive impacts of weather (and hence, high-variance climate change) on skier activity. These results elaborate conclusions from our previous annual-level analysis. More broadly, they illustrate the potential for using ARMAX models to conduct integrated, dynamic analysis across environmental and social domains

Modeling economic, biophysical, and environmental dynamics of potato production system

The adoption and use of diversified cropping practices has become widely accepted by producers. However, the profitability of an enterprise is dependent on the biophysical and economic factors. The biophysical factors determine the enterprise relationship among the various crops, their interactions with the ecosystem, and how each of them fits into the overall management plan. The economic factors determine the relative advantage of each crop and service in the farm plan. Although there have been experimental studies in Canada examining the impacts of rotations on the agronomics of field crops, there is limited research in modeling economic and environmental dynamics of the potato production system. Potato production in Manitoba has rapidly increased in recent years and became the second largest potato producer in Canada producing about 22.2% of the total Canada's potato production as of 2004. Alberta has had similar expansion with the highest yield per acre in Canada. The expansion of potato industry in these two provinces and other parts of Canada has created some concerns about agro-environmental indicators such as water contamination, soil erosion and long-term profitability of potato production practices. The objective of this study was to address some of these concerns and develop a dynamic model that integrates environmental and economic components of potato production systems and estimates sustainability of some of the agricultural practices. A Stella Modeling framework was developed to provide crop production and environmental input to an economic model of potato rotations. The economic performance of different potato rotations ranging from two to four years in duration, and containing potatoes in combination with oilseed, cereal, forage, and legume crops was evaluated based on standard budgeting techniques. Net income was estimated as the income remaining above cash costs (i.e., seed, fertilizer, chemical, fuel and oil, repairs, crop insurance premium, miscellaneous, land taxes, and interest cost on variable inputs), ownership costs (depreciation, interest on investment, and insurance and housing) for machinery and grain storage, and labour. All annual inputs used in each phase of rotation for each management treatment, the type and frequency of field operation, year and replicate including pre-plant activities, tillage, fertilization, planting, insects and pests control, harvesting, storage, and transportation were included in the analysis. Modelling the economics of irrigated potato rotations required input from an agro-environmental model. This agro-environmental model was developed to simulate nutrient dynamics, soil moisture dynamics, soil characteristics and erosion, soil organic matter content, residue decomposition, and crop growth. The economic model takes into account economic factors and costs that are influenced by yield function, nutrients and crop water thus establishing the link between the agro-environmental module and the economic module. Farm operation costs in our model are divided into two categories: dependent costs and base costs. Dependent costs are costs that are controlled by the agro-environmental module, including yield dependent costs, irrigation dependent costs and fertilizer dependent costs. Base costs were developed through experimental evaluation with E-Views and remain constant throughout the rotation. On the agro-environmental side, the model outputs the changes in soil organic matter, soil loss due to erosion, and carbon dioxide emission due to decomposition and mineralization. Results of the model show that changes in these variables are dependent upon the length of, and the crops involved in, the rotation. The economic model results showed highest average net revenue was found in shorter two-year rotations due to the greater frequency of potato.Crop Production/Industries,

Improved soil management and cropping systems for waterlog-prone soils : results of the 2000 season

The results of the fourth year of a five year research and development project to develop soil management practices and cropping systems to prevent waterlogging and increase the productivity of waterlogged lands in Western Australia. The concept of raised beds was used to alleviate or prevent waterlogging

Raised beds prevent waterlogging and increase productivity

Permanent Raised Beds are proving to be a revolutionary means of preventing waterlogging and a substantially increasing the productivity of wet and poorly productive land in Western Australia. In just three years, a research project has seen significant improvements in yield and reductions in waterlogging

Improved soil management and cropping systems for waterlog-prone soils : results of the 1999 season

The project aim was to map the distribution of waterlogging occurrences relative to soil type and climate; to develop soil, water and crop management practices applied to the concept of raised beds to alleviate or prevent waterlogging; to establish the economics of raised bed farming, relative to geographic location and waterlogging frequency

A Manual for raised bed farming in Western Australia

This manual provides a complete set of information on the nature, location, occurrence and reasons for waterlogging and how to prevent it. The preventative technology, raised bed farming, is explained in terms of: how and why it works; the practical means of installing and maintaining a bedding system; the cropping practices and machinery adaptations needed to effectively farm raised beds; and, the improved productivity and profitability that result from its adoption. The geographic distribution of water.https://researchlibrary.agric.wa.gov.au/bulletins/1032/thumbnail.jp

Crop Updates 2000 - Cereals part 1

This session covers eleven papers from different authors: PLENARY PAPERS 1. New Wheat for a Secure, Sustainable Future, Timothy G. Reeves, Sanjaya Rajaram, Maarten van Ginkel, Richard Trethowan, Hans-Joachim Braun, and Kelly Cassaday, International Maize and Wheat Improvement Centre (CIMMYT) 2. Managing Cereal Rusts - a National Perspective, R.A. McIntosh, University of Sydney Plant Breeding Institute, New South Wales 3. Managing Cereal Rusts in 2000 - a regional imperative, R. Loughman, Agriculture Western Australia 4. Is nutrition the answer to wheat after canola problems?Ross Brennan1, Bill Bowden1, Mike Bolland1, Zed Rengel2 and David Isbister2 1 Agriculture Western Australia 2University of Western Australia 5. Improved Sandplain Cropping Systems by Controlled Traffic, Dr Paul Blackwell, Agriculture Western Australia 6. Raised bed farming for improved cropping of waterlogged soils, Derk Bakker, Greg Hamilton, David Houlbrooke, Cliff Spann and Doug Rowe, Agriculture Western Australia 7. Banded Urea increased wheat yields, Patrick Gethin, Stephen Loss, Frank Boetel, and Tim O’Dea, CSBP futurefarm 8. Flexi N is as effective as Urea on wheat and canola, Frank Boetel, Stephen Loss, Patrick Gethin, and Tim O’Dea CSBP futurefarm 9. Why potassium may reduce cereal leaf disease, Noeleen Edwards, Agriculture Western Australia 10, Trace elements, Wayne Pluske CSBP futurefarm, and Ross BrennanAgriculture Western Australia 11. Historical Nutrient Balance at Paddock and Whole Farm scales for typical wheatbelt farms in the Dowerin - Wongan Hills area, M.T.F. Wong, K. Wittwer and H. Zhang Precision Agriculture Research Group, CSIRO Land and Wate

Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

Observation of two new Ξb−\Xi_b^- baryon resonances

Two structures are observed close to the kinematic threshold in the $\Xi_b^0 \pi^-$ mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content $bds$ are expected in this mass region: the spin-parity $J^P = \frac{1}{2}^+$ and $J^P=\frac{3}{2}^+$ states, denoted $\Xi_b^{\prime -}$ and $\Xi_b^{*-}$. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be $m(\Xi_b^{\prime -}) - m(\Xi_b^0) - m(\pi^{-}) = 3.653 \pm 0.018 \pm 0.006$ MeV$/c^2$, $m(\Xi_b^{*-}) - m(\Xi_b^0) - m(\pi^{-}) = 23.96 \pm 0.12 \pm 0.06$ MeV$/c^2$, $\Gamma(\Xi_b^{*-}) = 1.65 \pm 0.31 \pm 0.10$ MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of $\Gamma(\Xi_b^{\prime -}) < 0.08$ MeV at 95% confidence level. Relative production rates of these states are also reported.Comment: 17 pages, 2 figure