Sea-level variability in the Caribbean Sea over the last century

Mean sea level rise exposes coasts to increasing risks. For the Caribbean Sea, the regional and local sea-level behaviour is not well known. This study has investigated the sea level behavior in the region at different frequencies during the last century, to provide updated, accurate and useful information to implement coastal adaptation responses to sea-level hazards. Time series from 28 tide-gauges, 18 years of altimetry and various atmospheric and oceanographic climatologies have been used. Several new results have been found. The small Caribbean tides have significant long-term modulations. The net effect of the low frequency modulation of the tidal signal can change the maximum tidal range up to 23.5%. The seasonal sea level cycle is characterized by large spatial and temporal variability. The amplitude of the coastal annual harmonic ranges from 2 cm to 9 cm, peaking between August and October. The amplitude of the semi-annual harmonic has maximum amplitude of 6 cm but it is not significant at all stations. The barometric effect dominates the coastal semi-annual cycle, but it is insignificant in all the other sea level frequencies at the tide-gauges. The seasonal sea level cycle from altimetry confirms the results obtained from the tide-gauges and allows the identification of some dominant sea level forcing parameters such as the Panama-Colombia gyre driven by the wind stress curl and the Caribbean Low Level Jet modulating the sea level in the northern coast of South America and linked to the local upwelling. The basin average mean sea level rise from altimetry is 1.7±1.3 mm yr-1 for the period 1993-2010. Wind forcing changes causes the trends in the southern part of the basin, modulating the sea level through changes in the ocean circulation. Significant spatial and decadal variability of the trends is found. Secular coastal sea-level trends range from 1.3±0.2 mm yr-1 in Magueyes, where the steric contribution dominates, to 5.3±0.3 mm yr-1 in Cartagena, where other contributors including local vertical land movements are significant. Temporal changes in the sea level extremes are significant but in line with mean sea-level trends at each tide gauge. With the annual mean sea level removed, extremes range between 36 cm and 79 cm, the later recorded in Port Spain and caused by the largest tidal signal. The largest nontidal residual is 76 cm found in Magueyes, forced by a hurricane induced storm surge, however larger surges can occur in the basin. The interannual sea level signal and nontidal extremes correlate with El Niño-Southern Oscillation at different time and spatial scales. No correlation with the North Atlantic Oscillation is found at any frequency. The largest sea flooding probability in the Caribbean coasts is around October, when the different sea level contributors’ maximums interact. These sea flooding events are going to became more frequent in the future due to the secular mean sea level rise affecting the basin

Sea level extremes in the Caribbean Sea

Sea level extremes in the Caribbean Sea are analyzed on the basis of hourly records from 13 tide gauges. The largest sea level extreme observed is 83 cm at Port Spain. The largest nontidal residual in the records is 76 cm, forced by a category 5 hurricane. Storm surges in the Caribbean are primarily caused by tropical storms and stationary cold fronts intruding the basin. However, the seasonal signal and mesoscale eddies also contribute to the creation of extremes. The five stations that have more than 20 years of data show significant trends in the extremes suggesting that flooding events are expected to become more frequent in the future. The observed trends in extremes are caused by mean sea level rise. There is no evidence of secular changes in the storm activity. Sea level return periods have also been estimated. In the south Colombian Basin, where large hurricane-induced surges are rare, stable estimates can be obtained with 30 years of data or more. For the north of the basin, where large hurricane-induced surges are more frequent, at least 40 years of data are required. This suggests that the present data set is not sufficiently long for robust estimates of return periods. ENSO variability correlates with the nontidal extremes, indicating a reduction of the storm activity during positive ENSO events. The period with the highest extremes is around October, when the various sea level contributors' maxima coincide

Generalized Euler-Lagrange equations for variational problems with scale derivatives

We obtain several Euler-Lagrange equations for variational functionals defined on a set of H\"older curves. The cases when the Lagrangian contains multiple scale derivatives, depends on a parameter, or contains higher-order scale derivatives are considered.Comment: Submitted on 03-Aug-2009; accepted for publication 16-March-2010; in "Letters in Mathematical Physics"

Monitoring and modeling of household air quality related to use of different Cookfuels in Paraguay.

In Paraguay, 49% of the population depends on biomass (wood and charcoal) for cooking. Residential biomass burning is a major source of fine particulate matter (PM2.5 ) and carbon monoxide (CO) in and around the household environment. In July 2016, cross-sectional household air pollution sampling was conducted in 80 households in rural Paraguay. Time-integrated samples (24 hours) of PM2.5 and continuous CO concentrations were measured in kitchens that used wood, charcoal, liquefied petroleum gas (LPG), or electricity to cook. Qualitative and quantitative household-level variables were captured using questionnaires. The average PM2.5 concentration (μg/m3 ) was higher in kitchens that burned wood (741.7 ± 546.4) and charcoal (107.0 ± 68.6) than in kitchens where LPG (52.3 ± 18.9) or electricity (52.0 ± 14.8) was used. Likewise, the average CO concentration (ppm) was higher in kitchens that used wood (19.4 ± 12.6) and charcoal (7.6 ± 6.5) than in those that used LPG (0.5 ± 0.6) or electricity (0.4 ± 0.6). Multivariable linear regression was conducted to generate predictive models for indoor PM2.5 and CO concentrations (predicted R2  = 0.837 and 0.822, respectively). This study provides baseline indoor air quality data for Paraguay and presents a multivariate statistical approach that could be used in future research and intervention programs

Systematic screening as a strategy to increase services integration and revenues in Honduras

This operations research study, undertaken by the Honduras Family Planning Association (Asociación Hondureña de Planificación de Familia—ASHONPLAFA), tested the effectiveness of systematic screening to increase the number of services and revenue per visit in a reproductive health program. Despite monitoring plans, provider compliance with the intervention was low; the overall proportion of clients screened was less than 11 percent, and the frequency of screening varied greatly by clinic contact point. Although the study did not show an increase in the mean number of services per client, the negative results could reasonably be attributed to lack of implementation of the intervention. After consultation with the ASHONPLAFA marketing department, the executive director ordered that the strategy be implemented in all clinics, along with a system to monitor the utilization of a simplified screening form, designed to be less time consuming and less intrusive than the form tested during the experiment. The new form is limited to services most likely to be needed by clients, as indicated by the study’s analysis of unmet need and potential demand

Tracing sediment sources in an agriculture and livestock catchment of Argentina through the use of geochemical fingerprints

A mixing modelling approach (CSSIAR v2.00), using Energy Dispersive X Ray Fluorescence (EDXRF) and Total Organic Carbon (TOC) data as fingerprints for sediment sources and sinks, was applied for identifying critical hot spots of erosion in a typical Argentinian agro-ecosystem. The selected study site is the Estancia Grande catchment, covering 1235 hectares, which is located 23 km north east of San Luis (in the centre of Argentina). The studied catchment, which is characterized by highly erodible Haplic Kastanozem soils, is currently being used for agriculture (crop rotation), and livestock (free grazing and feedlots), and some fields are used for growing nut trees (walnuts and almonds) (Figure 1). Further fallow land is found in between the agriculture land and in the upper part of the catchment.Fil: Torres Astorga, Romina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Velasco, Ricardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Resch, C.. Organismo Internacional de Energía Atómica ; AustriaFil: Gruber, R.. Organismo Internacional de Energía Atómica ; AustriaFil: Padilla, R.. Organismo Internacional de Energía Atómica ; AustriaFil: Dercon, G.. Organismo Internacional de Energía Atómica ; AustriaFil: Mabit, L.. Organismo Internacional de Energía Atómica ; Austri

An approach to the physical geography of southern Quintana Roo, Yucatan Peninsula, Mexico

El presente trabajo analiza el medio físico del sur de Quintana Roo, Méjico, con el propósito de convertirse en un insumo de los futuros planes de ordenamiento y desarrollo territorial de la región. Para realizar el presente trabajo se recurrió a fuentes bibliográficas y cartográficas diversas y recorridos de campo en la franja costera de Mahahual-Xcalak, y Chetumal-Bacalar utilizando como georeferencia principal el Atlas digital de Costa Maya (2004). La principal aportación del trabajo es la realización de un diagnóstico de la geografía física del sur de Quintana Roo en la Península de Yucatán, de donde se podrán desprender nuevas líneas de investigación como la del turismo y el desarrollo regional y cohesión física y social en nuevos territorios turísticos de Méjico.The present work analyzes the physical environment of southern Quintana Roo, Mexico, with the aim of turning into a supply of management and territorial region development future plans To perform the present work we resorted to diverse bibliographical and cartographic sources and field tours in Mahahual-Xcalaks coastal band, and Chetumal-Bacalar using like georeference principally the digital Atlas of Mayan Coast (2004). The main contribution of the work is the accomplishment of a diagnosis of the physical geography of the south of Quintana Roo in the Yucatan Peninsula, from where new lines of investigation will be inferred like tourism ,regional development and physical-social cohesion in new tourist territories of Mexico.Fil: Velázquez Torres, David. México. Universidad de Quintana RooFil: Ceballos Martínez, Ricardo R.. México. Universidad de Quintana Ro

Submesoscale Rossby waves on the Antarctic circumpolar current.

The eastward-flowing Antarctic circumpolar current (ACC) plays a central role in the global ocean overturning circulation and facilitates the exchange of water between the ocean surface and interior. Submesoscale eddies and fronts with scales between 1 and 10 km are regularly observed in the upper ocean and are associated with strong vertical circulations and enhanced stratification. Despite their importance in other locations, comparatively little is known about submesoscales in the Southern Ocean. We present results from new observations, models, and theories showing that submesoscales are qualitatively changed by the strong jet associated with the ACC in the Scotia Sea, east of Drake Passage. Growing submesoscale disturbances develop along a dense filament and are transformed into submesoscale Rossby waves, which propagate upstream relative to the eastward jet. Unlike their counterparts in slower currents, the submesoscale Rossby waves do not destroy the underlying frontal structure. The development of submesoscale instabilities leads to strong net subduction of water associated with a dense outcropping filament, and later, the submesoscale Rossby waves are associated with intense vertical circulations