Spurious shifts in the pattern of diurnal variation of sea level pressure of reanalysis datasets

The main purpose of this work is to report the presence of spurious discontinuities in the pattern of diurnal variation of sea level pressure of the three reanalysis datasets from: the National Centers for Environmental Prediction (NCEP) and National Center for Atmospheric Science (R1), the NCEP and Department of Energy (R2), and the European Centre for Medium Range Weather Forecasting (ERA-40). Such discontinuities can be connected to the major changes in the global observing system that have occurred throughout reanalyses years. In the R1, the richest period in discontinuities is 1956-1958, coinciding with the start of modern radiosonde observation network. Rapid increase in the density of surface-based observations from 1967 also had an important impact on both R1 and ERA-40, with larger impact on R1. The reanalyses show discontinuities in the 1970s related to the assimilation of radiances measured by the Vertical Temperature Profile Radiometer and TIROS-N Operational Vertical Sounders onboard satellites. In the ERA-40, which additionally assimilated Special Sensor Microwave/Imager data, there are discontinuities in 1987-1989. The R1 also presents further discontinuities, in 1988-1993 likely connected to replacement/introduction of NOAA-series satellites with different biases, and to the volcanic eruption of Mount Pinatubo in June 1991, which is known to have severely affected measurements of infrared radiances for several years. The discontinuities in 1996-1998 might be partially connected to change in the type of radiosonde, from VIZ-B to VIZ-B2. The R2, which covers only satellite era (1979-on), shows discontinuities mainly in 1992, 1996-1997, and 2001. The discontinuities in 1992 and 2001 might have been caused by change in the satellite measurements and those in 1996-1997 by some changes in land-based observations network. © 2012 Springer-Verlag.

An assessment of the economic impact of climate change on the Agriculture, Coastal and Human Settlements and Health Sectors in Guyana

This report analyses the agriculture, coastal and human settlements and health sectors in Guyana to assess the potential economic impacts of climate change. The fundamental aim of this report is to assist with the development of strategies to deal with the potential impact of climate change on Guyana. It also has the potential to provide essential input for identifying and preparing policies and strategies to help bring the Caribbean sub-region closer to solving problems associated with climate change and attaining national and regional sustainable development goals. Some of the key anticipated manifestations of climate change for the Caribbean include elevated air and sea-surface temperatures, sea-level rise, possible changes in extreme events and a reduction in freshwater resources. The economic impact of climate change on the three sectors was estimated for the A2 and B2 IPCC scenarios until 2050 (agriculture and health sectors) and 2100 (coastal and human settlements sector). An exploration of various adaptation strategies was also undertaken for each sector using standard evaluation techniques. The study of the impact of climate change on the agriculture sector focused on three leading sub-sectors namely: sugar-cane, rice-paddy and fisheries. In estimating costs, the sugar sub-sector is projected to experience losses under A2 between US$ 144 million (at 4% discount rate) and US$300 million (1% rate); comparative statistics for rice are US$795 million and US$1577 million, respectively; while for fisheries, the results show that losses range from US$15 million (4% rate) and US$34 million (1% rate). In general, under the B2 scenarios, there are gains for sugar up to 2030 under all three discount rates while for rice the performance is somewhat better with gains realized under all three discount rates up to 2040. For fisheries, gains are forecasted under all three rates up to 2050, following marginal losses to 2020. In terms of the benefit-cost analysis conducted on selected adaptation measures under the A2 scenario, there were net benefits for all three commodities under all three discount rates. For the sugar-cane sub-sector these are: drainage and irrigation upgrade, purchase of new machinery for planting and harvesting, developing and replanting climate tolerant sugar-cane. The rice-paddy sub-sector will benefit from adaptive strategies, which include maintenance of drainage and irrigation systems, research and development, as well as education and training. Adaptation in the fisheries sub-sector must include measures such as, mangrove development and restoration and public education. The analysis of the coastal and human settlements sector has shown that based upon exposed assets and population, SLR can be classified as having the potential to create catastrophic conditions in Guyana. The main contributing factor is the concentration of socioeconomic infrastructure along the coastline in vulnerable areas.

An assessment of the economic impact of climate change on the coastal and human settlements, tourism and transport sectors in Barbados

This report analyses the coastal and human settlements, tourism and transport sectors in Barbados to assess the potential economic impact of climate change on the sectors. The fundamental aim of this report is to assist with the development of strategies to deal with the potential impact of climate change on Barbados. Some of the key anticipated manifestations of climate change for the Caribbean include elevated air and sea-surface temperatures, sea-level rise, possible changes in extreme events and a reduction in freshwater resources. The economic impact of climate change on the three sectors was estimated for the A2 and B2 IPCC scenarios until 2050 (tourism and transport sectors) and 2100 (coastal and human settlements sector). An exploration of various adaptation strategies was also undertaken for each sector using standard evaluation techniques. The analysis has shown that based upon exposed assets and population, SLR can be classified as having the potential to create potential catastrophe in Barbados. The main contributing factor is the concentration of socioeconomic infrastructure along the coastline in vulnerable areas. The A2 and B2 projections have indicated that the number of catastrophes that can be classified as great is likely to be increased for the country. This is based upon the possible effects of the projected unscheduled impacts to the economy both in terms of loss of life and economic infrastructure. These results arise from the A2 and B2 projections, thereby indicating that growth in numbers and losses are largely due to socioeconomic changes over the projection period and hence the need for increased adaptation strategies. A key adaptation measure recommended is for the government of Barbados to begin reducing the infrastructure deficit by continuously investing in protective infrastructure to decrease the country’s vulnerability to changes in the climate. With regard to the tourism sector, it was found that by combining the impacts due to a reduction in tourist arrivals, coral reef loss and SLR, estimated total economic impact of climate change is US $7,648 million (A2 scenario) and US $5,127 million (B2 scenario). An economic analysis of the benefits and costs of several adaptation options was undertaken to determine the cost effectiveness of each one and it was found that four (4) out of nine (9) options had high cost-benefit ratios. It is therefore recommended that the strategies that were most attractive in terms of the cost-benefit ratios be pursued first and these were: (1) enhanced reef monitoring systems to provide early warning alerts of bleaching events; (2) artificial reefs or fish-aggregating devices; (3) development of national adaptation plans (levee, sea wall and boardwalk); (4) revision of policies related to financing carbon neutral tourism; and (5) increasing recommended design wind speeds for new tourism-related structures. The total cost of climate change on international transportation in Barbados aggregated the impacts of changes in temperature and precipitation, new climate policies and SLR. The impact for air transportation ranges from US$10,727 million (B2 scenario) to US$12,279 million (A2 scenario) and for maritime transportation impact estimates range from US$1,992 million (B2 scenario) to US$2,606 million (A2 scenario). For international transportation as a whole, the impact of climate change varies from US$12,719 million under the B2 scenario to US$14,885 million under the A2 scenario. Barbados has the institutions set up to implement adaptive strategies to strengthen the resilience of the existing international transportation system to climate change impacts. Air and sea terminals and facilities can be made more robust, raised, or even relocated as need be, and where critical to safety and mobility, expanded redundant systems may be considered.

An assessment of the economic impact of climate change on the agriculture sector in Trinidad And Tobago

The economic impact of climate change on root crop, fisheries and vegetable production for Trinidad and Tobago under the A2 and B2 scenarios were modeled, relative to a baseline ―no climate change‖ case, where the mean temperature and rainfall for a base period of 1980 – 2000 was assumed for the years up to 2050. Production functions were used, using ARMA specifications to correct for serial autocorrelation. For the A2 scenarios, rainfall is expected to fall by approximately 10% relative to the baseline case in the 2020s, but is expected to rise thereafter, until by the 2040s rainfall rises slightly above the mean for the baseline case. For the B2 scenario, rainfall rose slightly above the mean for the baseline case in the current decade, but falls steadily thereafter to approximately 15% by the 2040s. Over the same period, temperature is expected to increase by 1.34C and 1.37C under A2 and B2 respectively. It is expected that any further increase in rainfall should have a deleterious effect on root crop production as a whole, since the above mentioned crops represent the majority of the root crops included in the study. Further expected increases in temperature will result in the ambient temperature being very close to the optimal end of the range for most of these crops. By 2050, the value of yield cumulative losses (2008$) for root crops is expected to be approximately 248.8 million USD under the A2 scenario and approximately 239.4 million USD under the B2 scenario. Relative to the 2005 catch for fish, there will be a decrease in catch potential of 10 - 20% by 2050 relative to 2005 catch potentials, other things remaining constant. By 2050 under the A2 and B2 scenarios, losses in real terms were estimated to be 160.2 million USD and 80.1 million USD respectively, at a 1% discount rate. For vegetables, the mean rainfall exceeds the optimal rainfall range for sweet peppers, hot peppers and melongene. However, while the optimal rainfall level for tomatoes is 3000mm/yr, other vegetables such as sweet peppers, hot peppers and ochroes have very low rainfall requirements (as low as 300 mm/yr). Therefore it is expected that any further decrease in rainfall should have a mixed effect on individual vegetable production. It is expected that any further increase in temperature should have a mixed effect on individual vegetable production, though model results indicated that as a group, an increase in temperature should have a positive impact on vegetable production. By 2050, the value of yield cumulative gains (2008$) for vegetables is expected to be approximately 54.9 million USD under the A2 scenario and approximately 49.1 million USD under the B2 scenario, given a 1% discount rate. For root crops, fisheries and vegetables combined, the cumulative loss under A2 is calculated as approximately 352.8 million USD and approximately 270.8 million USD under B2 by 2050. This is equivalent to 1.37% and 1.05% of the 2008 GDP under the A2 and B2 scenarios respectively by 2050. Sea Level Rise (SLR) by 2050 is estimated to be 0.255 m under A2 and 0.215 m under B2. GIS estimation indicated that for a 0.255 m sea level rise, combined with a 0.5 m high tide, there would be no permanent inundation of agricultural land in Trinidad. The total inundation area is 1.18 km2. This occurs only in the Caroni Watershed, on the western coast of Trinidad, and the areas are outside the Caroni Swamp. Even with an additional rise of 0.5 m to simulate a high rainfall event, the estimated inundated area is 4.67 km2, but with no permanent inundation, though likely to be subject to flooding. Based on eleven (11) evaluation criteria, the top potential adaptation options were identified: 1. Use of water saving irrigation systems and water management systems e.g. drip irrigation; 2. Mainstream climate change issues into agricultural management; 3. Repair/maintain existing dams; 4. Alter crop calendar for short-term crops; 5. Adopt improved technologies for soil conservation; 6. Establish systems of food storage; 7. Promote water conservation – install on-farm water harvesting off roof tops; 8. Design and implement holistic water management plans for all competing uses; 9. Build on- farm water storage (ponds and tanks); 10. Agricultural drainage; and 11. Installation of greenhouses. The most attractive adaptation options, based on the Benefit-Cost Ratio are: (1) Build on- farm water storage such as ponds and tanks (2) Mainstreaming climate change issues into agricultural management and (3) Water Harvesting. However, the options with the highest net benefits are, (in order of priority): (1) Build on- farm water storage such as ponds and tanks, (2) Mainstreaming climate change issues into agricultural management and (3) Use of drip irrigation. Based on the area burnt in Trinidad and Tobago between 2005 and 2009, the average annual loss due to fires is 1717.3 ha. At US$17.41 per carbon credit, this implies that for the total land lost to forest fires on average each year, the opportunity cost of carbon credit revenue is 74.3 million USD. If a teak reforestation programme is undertaken in Trinidad and Tobago, the net benefit of reforestation under a carbon credit programme would be 69 million USD cumulatively to 2050.

Sea Level Variations from Decades to Millennia: A few Case Studies

The main goals of this Ph.D. study are to investigate the regional and global geophysical components related to present polar ice melting and to provide independent cross validation checks of GIA models using both geophysical data detected by satellite mission, and geological observations from far field sites, in order to determine a lower and upper bound of uncertainty of GIA effect. The subject of this Thesis is the sea level change from decades to millennia scale. Within ice2sea collaboration, we developed a Fortran numerical code to analyze the local short-term sea level change and vertical deformation resulting from the loss of ice mass. This method is used to investigate polar regions: Greenland and Antarctica. We have used mass balance based on ICESat data for Greenland ice sheet and a plausible mass balance for Antarctic ice sheet. We have determined the regional and global fingerprint of sea level variations, vertical deformations of the solid surface of the Earth and variations of shape of the geoid for each ice source mentioned above. The coastal areas are affected by the long wavelength component of GIA process. Hence understanding the response of the Earth to loading is crucial in various contexts. Based on the hypothesis that Earth mantle materials obey to a linear rheology, and that the physical parameters of this rheology can be only characterized by their depth dependence, we investigate the Glacial Isostatic Effect upon the far field sites of Mediterranean area using an improved SELEN program. We presented new and revised observations for archaeological fish tanks located along the Tyrrhenian and Adriatic coast of Italy and new RSL for the SE Tunisia. Spatial and temporal variations of the Holocene sea levels studied in central Italy and Tunisia, provided important constraints on the melting history of the major ice sheets.

Sea-Level climate variability in the Mediterranean Sea

Sea-level variability is characterized by multiple interacting factors described in the Fourth Assessment Report (Bindoff et al., 2007) of the Intergovernmental Panel on Climate Change (IPCC) that act over wide spectra of temporal and spatial scales. In Church et al. (2010) sea-level variability and changes are defined as manifestations of climate variability and change. The European Environmental Agency (EEA) defines sea level as one of most important indicators for monitoring climate change, as it integrates the response of different components of the Earths system and is also affected by anthropogenic contributions (EEA, 2011). The balance between the different sea-level contributions represents an important source of uncertainty, involving stochastic processes that are very difficult to describe and understand in detail, to the point that they are defined as an enigma in Munk (2002). Sea-level rate estimates are affected by all these uncertainties, in particular if we look at possible responses to sea-level contributions to future climate. At the regional scale, lateral fluxes also contribute to sea-level variability, adding complexity to sea-level dynamics. The research strategy adopted in this work to approach such an interesting and challenging topic has been to develop an objective methodology to study sea-level variability at different temporal and spatial scales, applicable in each part of the Mediterranean basin in particular, and in the global ocean in general, using all the best calibrated sources of data (for the Mediterranean): in-situ, remote-sensig and numerical models data. The global objective of this work was to achieve a deep understanding of all of the components of the sea-level signal contributing to sea-level variability, tendency and trend and to quantify them.

Sea level measurement using single GNSS antenna SNR signals

This thesis presents a possible method to calculate sea level variation using geodetic-quality Global Navigate Satellite System (GNSS) receivers. Three antennas are used: two small antennas and a choke ring one, analyzing only Global Positioning System signals. The main goal of the thesis is to test a modified configuration for antenna set up. In particular, measurements obtained tilting one antenna to face the horizon are compared to measurements obtained from antennas looking upward. The location of the experiment is a coastal environment nearby the Onsala Space Observatory in Sweden. Sea level variations are obtained using periodogram analysis of the SNR signal and compared to synthetic gauge generated from two independent tide gauges. The choke ring antenna provides poor result, with an RMS around 6 cm and a correlation coefficients of 0.89. The smaller antennas provide correlation coefficients around 0.93. The antenna pointing upward present an RMS of 4.3 cm and the one pointing the horizon an RMS of 6.7 cm. Notable variation in the statistical parameters is found when modifying the length of the interval analyzed. In particular, doubts are risen on the reliability of certain scattered data. No relation is found between the accuracy of the method and weather conditions. Possible methods to enhance the available data are investigated, and correlation coefficient above 0.97 can be obtained with small antennas when sacrificing data points. Hence, the results provide evidence of the suitability of SNR signal analysis for sea level variation in coastal environment even in the case of adverse weather conditions. In particular, tilted configurations provides comparable result with upward looking geodetic antennas. A SNR signal simulator is also tested to investigate its performance and usability. Various configuration are analyzed in combination with the periodogram procedure used to calculate the height of reflectors. Consistency between the data calculated and those received is found, and the overall accuracy of the height calculation program is found to be around 5 mm for input height below 5 m. The procedure is thus found to be suitable to analyze the data provided by the GNSS antennas at Onsala.

Global and regional sea level variations in the recent past and future: insight from observations and modeling

This work is focused on the analysis of sea–level change (last century), based mainly on instrumental observations. During this period, individual components of sea–level change are investigated, both at global and regional scales. Some of the geophysical processes responsible for current sea-level change such as glacial isostatic adjustments and current melting terrestrial ice sources, have been modeled and compared with observations. A new value of global mean sea level change based of tide gauges observations has been independently assessed in 1.5 mm/year, using corrections for glacial isostatic adjustment obtained with different models as a criterion for the tide gauge selection. The long wavelength spatial variability of the main components of sea–level change has been investigated by means of traditional and new spectral methods. Complex non–linear trends and abrupt sea–level variations shown by tide gauges records have been addressed applying different approaches to regional case studies. The Ensemble Empirical Mode Decomposition technique has been used to analyse tide gauges records from the Adriatic Sea to ascertain the existence of cyclic sea-level variations. An Early Warning approach have been adopted to detect tipping points in sea–level records of North East Pacific and their relationship with oceanic modes. Global sea–level projections to year 2100 have been obtained by a semi-empirical approach based on the artificial neural network method. In addition, a model-based approach has been applied to the case of the Mediterranean Sea, obtaining sea-level projection to year 2050.

The importance of ship log data: reconstructing North Atlantic, European and Mediterranean sea level pressure fields back to 1750

Local to regional climate anomalies are to a large extent determined by the state of the atmospheric circulation. The knowledge of large-scale sea level pressure (SLP) variations in former times is therefore crucial when addressing past climate changes across Europe and the Mediterranean. However, currently available SLP reconstructions lack data from the ocean, particularly in the pre-1850 period. Here we present a new statistically-derived 5° × 5° resolved gridded seasonal SLP dataset covering the eastern North Atlantic, Europe and the Mediterranean area (40°W–50°E; 20°N–70°N) back to 1750 using terrestrial instrumental pressure series and marine wind information from ship logbooks. For the period 1750–1850, the new SLP reconstruction provides a more accurate representation of the strength of the winter westerlies as well as the location and variability of the Azores High than currently available multiproxy pressure field reconstructions. These findings strongly support the potential of ship logbooks as an important source to determine past circulation variations especially for the pre-1850 period. This new dataset can be further used for dynamical studies relating large-scale atmospheric circulation to temperature and precipitation variability over the Mediterranean and Eurasia, for the comparison with outputs from GCMs as well as for detection and attribution studies.

Future storm surge impacts on insurable losses for the North Sea region

The influence of climate change on storm surges including increased mean sea level change and the associated insurable losses are assessed for the North Sea basin. In doing so, the newly developed approach couples a dynamical storm surge model with a loss model. The key element of the approach is the generation of a probabilistic storm surge event set. Together with parametrizations of the inland propagation and the coastal protection failure probability this enables the estimation of annual expected losses. The sensitivity to the parametrizations is rather weak except when the assumption of high level of increased mean sea level change is made. Applying this approach to future scenarios shows a substantial increase of insurable losses with respect to the present day. Superimposing different mean sea level changes shows a nonlinear behavior at the country level, as the future storm surge changes are higher for Germany and Denmark. Thus, the study exhibits the necessity to assess the socio-economic impacts of coastal floods by combining the expected sea level rise with storm surge projections.