Diagnostic Indicators in Trough - Ridge Systems applied to Real Time Ship Routeing

The need for the mariner to have better weather indicators for efficient ship routeing in the middle latitudes is demonstrated. The benefits of an early appreciation of the subtle changes in storm behaviour is shown in a case study. Monitoring of ship's performance through a frontal depression using a modified Tropical Storm Avoidance simulation, also developed by the author, shows the penalties of not minimising the effects of wind and waves. To accomplish the aims of this project diagnostic models are developed, firstly to show the overall movement of the frontal depression within the trough - ridge system and secondly to investigate the field structure appertaining to depression movement and development. The graphical diagnostic model, an animated movie loop, allows the detail from two levels to be combined, surface fronts superimposed on the 500 mb flow, and played back in sequence showing the sophisticated nature of storm movement. This insight naturally lead to the development of a numerical diagnostic model to study simple elements such as wind fields. Analysis of these data enabled a movement indicator for the frontal depression, the "TEN" Indicator, to be formulated and is based on the 500 mb contours. Further improvements in the diagnostic numerical model allows the gradients of synthesised elements to be calculated without the loss of boundary values, and uses a cubic spline technique based on the Lagrange Interpolation. Error analysis of the calculated wind fields is carried out to test the accuracy of the methods employed. The model is then used to analyse a number of depressions using various development techniques to test the model. The results from four occasions, of the many observed, are demonstrated showing the development ideas of Sutcliffe, Petterssen and the Q-Vector based on quasi-geostrophic theory. Divergence is also considered using gradient wind substitutions, adjusted for surface friction and modified to satisfy curvature effects in ridge systems. The four occasions illustrated demonstrates the similarities between each method, the location of vertical motion within a deepening depression is located slightly in advance of the warm front. The normalising of these vertical field indicators against the surrounding flow allows the visual and numerical appreciation of ascent in weak fields. This approach may be an advantage in further studies of cyclogenesis. The model wind fields are tested using operational wind data, both being calculated from the same digitised pressure fields. The Oceanroutes Operational Routeing Model is employed, using these data, to produce two routes using both the analysis and forecast data. The case study demonstrates the usefulness of the "TEN" Movement Indicator as it provides the mariner with the tools to examine depression movement, to check forecasts and to give him the confidence to question routeing orders. This method requires data for the surface and the 500 mb level. Recommendations are suggested to modify the surface weather chart format for the mariner by including both movement and development information which would economise and optimise weather data transmission for greater shipboard efficiency.Plymouth Weather Centre, Meteorological Office, Plymout

Tax Compliance as a Wicked System

This Article proposes a new typology and framework for tax compliance systems. Traditionally-competing approaches such as deterrence theory, behaviorist theory, and game theoretic models taken together suggest that tax compliance is perhaps a new type of system—a “wicked system”—that is only partially comprehensible by understanding the traditional theories alone. If correct, previously competing theories become simply different limiting cases of the same underlying “wicked system.” The Article concludes with a discussion of the framework’s limitations and presents initial solutions and challenges for future work

There is No Spoon: Reconsidering the Tax Compliance Puzzle

For over 40 years theorists have sought the effects of tax audits on voluntary compliance rates by studying individual taxpayer motivations. Yet no single theory has produced a taxpayer incentive model that both comports with experience and explains the effects of audits on compliance. This quandary is often termed the “tax compliance puzzle.” Consequently, some theorists have called for more capacious models that make room for the panoply of individual compliance motivations. This Article proposes that a more complex model is unnecessary. To the contrary, complex compliance and enforcement data can result from extremely simple behavioral rules of individual taxpayers and government examiners interacting over time. This Article describes an agent-based computational model that uses a single, simple rule of action for each taxpayer and examiner. The model produces three interesting effects supporting the conclusion that there may be no tax compliance puzzle to solve. First, the results comport with known U.S. compliance and audit rates. Second, the results suggest that while audit probability influences individual compliance decisions, it has negligible effects on system-level compliance patterns. Third, the results support the theory that the perceived strength of the tax authority correlates directly—but nonlinearly—with voluntary compliance rates. The model is not complete enough to determine conclusively that this last effect is due to perceived strength of the tax authority alone and might be due instead to factors such as social norms and other behaviorist theories

Constraints on IRS Control: An Alternative Approach to Tax Gap Analysis

A tax authority wants to take actions it knows will foster the greatest degree of voluntary taxpayer compliance to reduce the “tax gap.” This paper suggests that even if a tax authority could attain a state of complete knowledge, there are constraints on whether and to what extent such actions would result in reducing the macro-level tax gap. These limits are not merely a consequence of finite agency resources. They are inherent in the system itself. To show that this is one possible interpretation of the tax gap data, the paper formulates known results in a different way by analyzing tax compliance as a population with a single covariate. This leads to a standard use of the logistic map to analyze the dynamics of non-compliance growth or decay over a sequence of periods. This formulation gives the same results as the tax gap studies performed over the past fifty years in the U.S. given the published margins of error. Limitations and recommendations for future work are discussed, along with some implications for tax policy

Queries

Queries by Elaine Geering, Rowan Gibbs and Bill Manhire

Approach to management of the Mokau coal resource

The Mokau Coalfield, North Taranaki, New Zealand contains about 73 million tonnes of mineable coal which may be required to fire a 1000 MW thermal power station. Planning for development of the coalfield is at an early stage and current investigations are oriented towards coal resource measurement and infrastructure requirements. The predominantly rural environment of the Mokau Coalfield region will suffer a number of impacts if coal development is to proceed at the proposed scale. Early recognition of these impacts, together with recognition of possible constraints on development, is desirable so that development planning may maximise environmental benefits. Traditionally coal development does not incorporate environmental information until the late feasibility stage of planning. It is however desirable to initiate environmental management planning at an early stage of coal resource development planning. Early inclusion of environmental aspects is possible and an approach to environmentally aware management of the Mokau coal resource is illustrated. The approach relies on development of a materials balance for both mining and use sectors of the development. The materials balance details inputs to the development (i.e. resource requirements) and identifies all outputs as primary product, increased inventory or residuals. A planning framework is described whereby environmental factors are incorporated into mainstream planning at the pre-feasibility stage. A number of potential impacts and constraints are identified in this largely indicative study. Before all impacts and constraints can be identified a more detailed study, using the methods developed here, is warranted

Queries

Queries by Elaine Geering, Rowan Gibbs and Bill Manhire

Dairy Cattle Genetics by Environment Interaction Mismatch Contributes to Poor Mitigation and Adaptation of Grazing Systems to Climate Change Actions in the Peruvian High Andes: A Review

The high Andes of Peru includes fragile ecosystems. Nevertheless, it plays important ecosystem functions (e.g., biodiversity, water supply for the lowlands, CO2 sinks in soil, etc). More than 80% of the livestock population of Peru is farmed in this area, supporting the livelihood of approximately 1’400,000 poor families, who are vulnerable to climate change (CC). Climate change in the high Andes is occurring at accelerated rates, compared to lowlands regions. Prevalent factors in the high Andes, such as hypoxia, high UV radiation, climatic extremes, large variation between maximum and minimum temperatures, seasonality in rainfall (determining highly seasonal forage growth) and CC, not only increase the feed and water needs of animals, but also affect animal production, reproduction, rumen function and welfare, making them more vulnerable to CC. During the last three decades, livestock farming in the high Andes has undergone transformation. The farming of camelids and creole species has been almost replaced by smallholder dairying, which have a higher environmental footprint. Institutions promoting dairying neglect the fitness requirement for the animal genetics to perform in such environments. Recent work of the New Zealand Peru Dairy Support Project (NZPDSP; 2016‒2020) demonstrated that rapid and significant improvements in animal productivity and profitability of dairying can be achieved by promoting adoption of simple and low-cost husbandry practices. Nevertheless, further improvements are constrained by the unfitness of the current animal genetics. Here, based on a literature review and experience from the NZPDSP, we propose a search for dairy cattle genetics that contributes to mitigation and adaptation to CC, while enhancing the livelihoods of the poor