630 resultados para Wilhite, Clayton


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There are significant, fundamental changes taking place in global air and sea surface temperatures and sea levels. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change noted that many of the warmest years on the instrumental record of global surface temperatures have occurred within the last twelve years, i.e. 1995-2006 (IPCC, 2007). The Caribbean tourism product is particularly vulnerable to climate change. On the demand side, mitigation measures in other countries – for example, measures to reduce the consumption of fossil fuels – could have implications for airfares and cruise prices and, therefore, for the demand for travel, particularly to long-haul destinations such as the Caribbean (Clayton, 2009). On the supply side, sea level rise will cause beaches to disappear and damage coastal resorts. Changes in the frequency and severity of hurricanes are likely to magnify that damage. Other indirect impacts on the tourism product include rising insurance premiums and competition for water resources (Cashman, Cumberbatch, & Moore, 2012). The present report has used information on historic and future Caribbean climate data to calculate that the Caribbean tourism climatic index (TCI) ranges from −20 (impossible) to +100 (ideal). In addition to projections for the Caribbean, the report has produced TCI projections for the New York City area (specifically, Central Park), which have been used as comparators for Caribbean country projections. The conditions in the source market provide a benchmark against which visitors may judge their experience in the tourism destination. The historical and forecasted TCIs for the Caribbean under both the A2 and B2 climate scenarios of the IPCC suggest that climatic conditions in the Caribbean are expected to deteriorate, and are likely to become less conducive to tourism. More specifically, the greatest decline in the TCI is likely to occur during the northern hemisphere summer months from May to September. At the same time, the scenario analysis indicates that home conditions during the traditional tourist season (December – April) are likely to improve, which could make it more attractive for visitors from these markets to consider ‘staycations’ as an alternative to overseas trips.

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This report provides an analysis and evaluation of the likely effects of climate change on the tourism sector in Montserrat. Clayton (2009) identifies three reasons why the Caribbean should be concerned about the potential effects of climate change on tourism: (a) the relatively high dependence on tourism as a source of foreign exchange and employment; (b) the intrinsic vulnerability of small islands and their infrastructure (e.g. hotels and resorts) to sea level rise and extreme climatic events (e.g. hurricanes and floods); and, (c) the high dependence of the regional tourist industry on carbon-based fuels (both to bring tourist to the region as well as to provide support services in the region). The effects of climate change are already being felt on the island. Between 1970 and 2009, there was a rise in the number of relatively hot days experienced on the island. Added to this, there was also a decline in mean precipitation over the period. Besides temperature, there is also the threat of wind speeds. Since the early 20th century, the number of hurricanes passing through the Caribbean has risen from about 5-6 per year to more than 25 in some years of the twenty-first century. In Montserrat, the estimated damage from four windstorms (including hurricanes) affecting the island was US$260 million or almost five times 2009 gross domestic product (GDP). Climate change is also likely to significantly affect coral reefs. Hoegh-Guldberg (2007) estimates that should current concentrations of carbon dioxide in the Earth’s atmosphere rise from 380ppm to 560ppm, decreases in coral calcification and growth by 40% are likely. The report attempted to quantify the likely effects of the changes in the climatic factors mentioned above. As it relates to temperature and other climatic variables, a tourism climatic index that captures the elements of climate that impact on a destination’s experience was constructed. The index was calculated using historical observations as well as those under two likely climate scenarios: A2 and B2. The results suggest that under both scenarios, the island’s key tourism climatic features will likely decline and therefore negatively impact on the destination experience of visitors. Including this tourism climatic index in a tourism demand model suggests that this would translate into losses of around 145% of GDP. As it relates to coral reefs, the value of the damage due to the loss of coral reefs was estimated at 7.6 times GDP, while the damage due to land loss for the tourism industry was 45% of GDP. The total cost of climate change for the tourism industry was therefore projected to be 9.6 times 2009 GDP over a 40-year horizon. Given the potential for significant damage to the industry, a large number of potential adaptation measures were considered. Out of these, a short-list of 9 potential options was selected using 10 evaluation criteria. These included: (a) Increasing recommended design wind speeds for new tourism-related structures; (b) Construction of water storage tanks; (c) Irrigation network that allows for the recycling of waste water; (d) Enhanced reef monitoring systems to provide early warning alerts of bleaching events; (e) Deployment of artificial reefs and fish-aggregating devices; (f) Developing national evacuation and rescue plans; (g) Introduction of alternative attractions; (h) Providing re-training for displaced tourism workers, and; (i) Revised policies related to financing national tourism offices to accommodate the new climatic realities Using cost-benefit analysis, three options were put forward as being financially viable and ready for immediate implementation: (a) Increase recommended design speeds for new tourism-related structures; (b) Enhance reef monitoring systems to provide early warning alerts of bleaching events, and; (c) Deploy artificial reefs or fish-aggregating devices. While these options had positive benefit cost ratios, other options were also recommended based on their non-tangible benefits: an irrigation network that allows for the recycling of waste water, development of national evacuation and rescue plans, providing retraining for displaced tourism workers and the revision of policies related to financing national tourism offices to accommodate the new climatic realities.

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This report provides an analysis and evaluation of the likely effects of climate change on the tourism sector in Saint Lucia. Clayton (2009) identifies three reasons why the Caribbean should be concerned about the potential effects of climate change on tourism: (a) the relatively high dependence on tourism as a source of foreign exchange and employment; (b) the intrinsic vulnerability of small islands and their infrastructure (e.g. hotels and resorts) to sea level rise and extreme climatic events (e.g. hurricanes and floods); and, (c) the high dependence of the regional tourist industry on carbon-based fuels (both to bring tourist to the region as well as to provide support services in the region). The effects of climate change are already being felt on the island. Between 1970 and 2009 there was a rise in the number of relatively hot days experienced on the island. Added to this, there was also a decline in mean precipitation over the period. In addition to temperature, there is also the threat of increased wind speeds. Since the early twentieth century, the number of hurricanes passing through the Caribbean has risen from about 5-6 per year to more than 25 in some years of the twenty-first century. In Saint Lucia, the estimated damage from 12 windstorms (including hurricanes) affecting the island was US$1 billion or about 106% of 2009 GDP. Climate change is also likely to significantly affect coral reefs. Hoegh-Guldberg (2007) estimates that should current concentrations of carbon dioxide in the Earth’s atmosphere rise from 380ppm to 560ppm, decreases in coral calcification and growth by 40% are likely. This report attempted to quantify the likely effects of the changes in the climatic factors mentioned above on the economy of Saint Lucia. As it relates to temperature and other climatic variables, a tourism climatic index that captures the elements of climate that impact on a destination’s experience was constructed. The index was calculated using historical observations, as well as those under two, likely, Special Report on Emissions Scenarios (SRES) climate scenarios: A2 and B2.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em História - FCHS

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Pós-graduação em Agronomia (Horticultura) - FCA

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Pós-graduação em Ciência da Informação - FFC

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The present work describes an alternative methodology for identification of aeroelastic stability in a range of varying parameters. Analysis is performed in time domain based on Lyapunov stability and solved by convex optimization algorithms. The theory is outlined and simulations are carried out on a benchmark system to illustrate the method. The classical methodology with the analysis of the system's eigenvalues is presented for comparing the results and validating the approach. The aeroelastic model is represented in state space format and the unsteady aerodynamic forces are written in time domain using rational function approximation. The problem is formulated as a polytopic differential inclusion system and the conceptual idea can be used in two different applications. In the first application the method verifies the aeroelastic stability in a range of air density (or its equivalent altitude range). In the second one, the stability is verified for a rage of velocities. These analyses are in contrast to the classical discrete analysis performed at fixed air density/velocity values. It is shown that this method is efficient to identify stability regions in the flight envelope and it offers promise for robust flutter identification.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz-1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO 600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties, for example the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well localized, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of O(10) for GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the method of the linear grid in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO 600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, under an assumption of a fixed GW emission energy of 10(-2)M circle dot c(2), with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events once the advanced LIGO and Virgo detectors begin operation.

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We present the results of a search for gravitational waves associated with 223 gamma-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M(circle dot)c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.