52 research outputs found

    A climatology of low level wind regimes over Central America using a weather type classification approach

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    Based on the potential of the weather types classification method to study synoptic features, this study proposes the application of such methodology for the identification of the main large scale patterns related with weather in Central America. Using ERA Interim low-level winds in a domain that encompasses the intra-Americas sea, the eastern tropical Pacific, southern North America, Central America and northern South America, the K-means clustering algorithm was applied to find recurrent regimes of low-level winds. Eleven regimes were identified and good coherency between the results and known features of regional circulation was found. It was determined that the main large scale patterns can be either locally forced or a response to tropical-extratropical interactions. Moreover, the local forcing dominates the summer regimes whereas mid latitude interactions lead to winter regimes. The study of the relationship between the large scale patterns and regional precipitation shows that winter regimes are related with the Caribbean-Pacific precipitation seesaw. Summer regimes, on the other hand, enhance the Caribbean-Pacific precipitation with contrasting distribution as a function of the dominant regimes. A strong influence of ENSO on the frequency and duration of the regimes was found. It was determined that the specific effect of ENSO on the regimes depends on whether the circulation is locally forced or lead by the interaction between the tropics and the mid-latitudes. The study of the cold surges using the information of the identified regimes revealed that three regimes are linkable with the occurrence of cold surges that affect Central America and its precipitation. As the winter regimes are largely dependent of mid-latitude interaction with the tropics, the effect that ENSO has on the Jet Stream is reflected in the winter regimes. An automated analysis of large scale conditions based on reanalysis and/or model data seems useful for both dynamical studies and as a tool to support forecasting. The application of the approach implemented in this study may be promising to improve current understanding on how large scale conditions affect regional weather.Universidad de Costa Rica/[805-B3-600]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

    Cambios futuros de precipitación y temperatura sobre América Central y el Caribe utilizando proyecciones climáticas de reducción de escala estadística

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    En la presente investigación se muestra mediante el uso del conjunto de proyecciones climáticas de reducción de escala estadística pertenecientes al NEX-GDDP, los cambios a largo plazo en precipitación y temperatura que ocurrirían en América Central y el Caribe a finales del siglo XXI, esto a través del cálculo de las diferencias de los ensambles de los multi-modelos de los dos escenarios correspondientes a las rutas de concentración representativas (RCP 4.5 y RCP 8.5) con un período de 2070-2099 menos el escenario histórico que abarca de 1970-1999. Vislumbrando como un acelerado aumento en las concentraciones de gases de efecto invernadero debido a la dependencia del uso excesivo de combustibles fósiles, traería consigo cambios en esta región, tales como condiciones más secas en países como Guatemala, Belice, Honduras, El Salvador, Nicaragua y Costa Rica, y de manera contraria condiciones más húmedas en la costa Pacífica de países como Colombia, Ecuador y Perú.The long-term changes in precipitation and temperature that will occur in Central America and the Caribbean at the end of the 21st century are shown using the NEX-GDDP statistical downscaled projections. We used this high resolution dataset to compute the differences between the multi-model ensembles of the two prospective scenarios corresponding to the representative concentration pathways (RCP 4.5 and RCP 8.5) with a period of 2070-2099 and the retrospective baseline scenario covering 1970-1999. Looking at how accelerated and unprecedented increases in concentrations of greenhouse gases will bring about changes in this region, such as drier conditions in countries like Guatemala, Belize, Honduras, El Salvador, Nicaragua and Costa Rica, and in the other hand wetter conditions in the Pacific coast of countries like Colombia, Ecuador and Peru.Universidad de Costa Rica/[805-B7-605]/UCR/Costa RicaUniversidad de Costa Rica/[805-B6-147]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

    Tracing Water Sources and Fluxes in a Dynamic Tropical Environment: From Observations to Modeling

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    Código de proyecto: Isotope Network for Tropical Ecosystem Studies (ISONet). Producción relacionada con el Observatorio del Agua y Cambio Global (OACG).Tropical regions cover approximately 36% of the Earth’s landmass. These regions are home to 40% of the world’s population, which is projected to increase to over 50% by 2030 under a remarkable climate variability scenario often exacerbated by El Niño Southern Oscillation (ENSO) and other climate teleconnections. In the tropics, ecohydrological conditions are typically under the influence of complex land-ocean-atmosphere interactions that produce a dynamic cycling of mass and energy reflected in a clear partition of water fluxes. Here, we present a review of 7 years of a concerted and continuous water stable isotope monitoring across Costa Rica, including key insights learned, main methodological advances and limitations (both in experimental designs and data analysis), potential data gaps, and future research opportunities with a humid tropical perspective. The uniqueness of the geographic location of Costa Rica within the mountainous Central America Isthmus, receiving moisture inputs from the Caribbean Sea (windward) and the Pacific Ocean (complex leeward topography), and experiencing strong ENSO events, poses a clear advantage for the use of isotopic variations to underpin key drivers in ecohydrological responses. In a sequential approach, isotopic variations are analyzed from moisture transport, rainfall generation, and groundwater/surface connectivity to Bayesian and rainfall-runoff modeling. The overarching goal of this review is to provide a robust humid tropical example with a progressive escalation from common water isotope observations to more complex modeling outputs and applications to enhance water resource management in the tropics.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de FísicaUCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Sociales::Escuela de Geografí

    Tracer-aided ecohydrological modelling across climate, land cover, and topographical gradients in the tropics

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    Funding Information: We thank the Leverhulme Trust funded ISOLAND (RPG‐2018‐375) project, the IAEA‐CRP F31005 contract 22904, the IAEA‐CRP F31006, and the IAEA‐CRP F31006 and UCR C1038 funded the IsoRSM project. We also acknowledge the many suggestions by two anonymous reviewers that improved this paper. Funding Information: We thank the Leverhulme Trust funded ISOLAND (RPG-2018-375) project, the IAEA-CRP F31005 contract 22904, the IAEA-CRP F31006, and the IAEA-CRP F31006 and UCR C1038 funded the IsoRSM project. We also acknowledge the many suggestions by two anonymous reviewers that improved this paper. Publisher Copyright: © 2023 The Authors. Hydrological Processes published by John Wiley & Sons Ltd.Peer reviewedPublisher PD

    Hyperspectral reflectance measurements from UAS under intermittent clouds: Correcting irradiance measurements for sensor tilt

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    One great advantage of optical hyperspectral remote sensing from unmanned aerial systems (UAS) compared to satellite missions is the possibility to fly and collect data below clouds. The most typical scenario is flying below intermittent clouds and under turbulent conditions, which causes tilting of the platform. This study aims to advance hyperspectral imaging from UAS in most weather conditions by addressing two challenges: (i) the radiometric and spectral calibrations of miniaturized hyperspectral sensors; and (ii) tilting effects on measured downwelling irradiance. We developed a novel method to correct the downwelling irradiance data for tilting effects. It uses a hybrid approach of minimizing measured irradiance variations for constant irradiance periods and spectral unmixing, to calculate the spectral diffuse irradiance fraction for all irradiance measurements within a flight. It only requires the platform's attitude data and a standard incoming light sensor. We demonstrated the method at the Palo Verde National Park wetlands in Costa Rica, a highly biodiverse area. Our results showed that the downwelling irradiance correction method reduced systematic shifts caused by a change in flight direction of the UAS, by 87% and achieving a deviation of 2.78% relative to a on ground reference in terms of broadband irradiance. High frequency (< 3 s) irradiance variations caused by high-frequency tilting movements of the UAS were reduced by up to 71%. Our complete spectral and radiometric calibration and irradiance correction can significantly remove typical striped illumination artifacts in the surface reflectance-factor map product. The possibility of collecting precise hyperspectral reflectance-factor data from UAS under varying cloud cover makes it more operational for environmental monitoring or precision agriculture applications, being an important step in advancing hyperspectral imaging from UAS.Innovation Fund Denmark/[7048-00001B]/IFD/DinamarcaAgricultural Water Innovations in the Tropics/[]/AgWIT/CanadáUniversidad de Costa Rica/[805-C0-603]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

    Diseño de infografías científicas en el aula a través de herramientas web 3.0 y recursos en abierto

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    El proyecto que se presenta pretende instruir a estudiantes y profesores en las competencias necesarias para el diseño y elaboración de infografías científicas de contenidos académicos, utilizando para ello herramientas de la web 3.0 disponibles en abierto. Exponer ideas científicas mediante la elaboración de infografías es una realidad que ha llegado ya a todos los hogares gracias a los medios de comunicación: al exponer noticias en papel o en web, los redactores ya no recurren únicamente al texto con imágenes, sino que se valen de elementos infográficos explicativos que ayudan a que el público comprenda mejor la noticia en su dimensión más técnica. Aplicar la metodología de realización de infografías científicas a la práctica docente en Humanidades y Ciencias Sociales (Historia del Arte, Historia Moderna, Educación, Psicología, Bellas Artes y Documentación) se presenta no solo como una estrategia útil para que los estudiantes sinteticen las claves de determinados temas, sino también como una herramienta interesante para dotar de competencias de difusión científica a los alumnos, facilitando así su inserción laboral. Asimismo, esta proyecto ha facilitado la conformación de un equipo innovador profundamente interdisciplinar (Historia, Historia del Arte, Psicología, Tecnologías y Bellas Artes) e interinstitucional (UCM, UNED y URJC) con un enorme potencial de cara a futuras propuestas de innovación docente

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Memoria del II Coloquio Internacional sobre Diversidad Cultural y Estudios Regionales

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    Desde la Sede de Occidente y, específicamente, en el seno de la Coordinación de Investigación y con el apoyo de la Dirección de la Sede y las Coordinaciones de Docencia, Administración y Acción Social, así como de la Vicerrectoría de Investigación, se han celebrado en el 2011 y en el 2012 dos coloquios internacionales sobre diversidad cultural y estudios regionales. El propósito de ambos consistió principalmente en motivar a investigadores e investigadoras de las distintas unidades académicas de la Universidad de Costa Rica y de otras instituciones de Educación Superior, así como a representantes de Centros e Institutos de Investigación nacionales e internacionales, a presentar resultados de investigaciones que contribuyeran a un mayor conocimiento de los procesos culturales y que dieran a conocer resultados que permitieran la comprensión de las realidades de distintos sectores y regiones. En el 2011 se presentaron cuarenta y seis ponencias y se dictaron tres conferencias magistrales, y en el 2012 se expusieron cincuenta ponencias y se impartieron tres conferencias magistrales.UCR::Sedes Regionales::Sede de Occidente::Recinto San Ramón::Centro de Investigaciones sobre Diversidad Cultural y Estudios Regionales (CIDICER

    Oceanic and terrestrial sources of continental precipitation

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    Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Reviews of Geophysics 50 (2012): RG4003, doi:10.1029/2012RG000389.The most important sources of atmospheric moisture at the global scale are herein identified, both oceanic and terrestrial, and a characterization is made of how continental regions are influenced by water from different moisture source regions. The methods used to establish source-sink relationships of atmospheric water vapor are reviewed, and the advantages and caveats associated with each technique are discussed. The methods described include analytical and box models, numerical water vapor tracers, and physical water vapor tracers (isotopes). In particular, consideration is given to the wide range of recently developed Lagrangian techniques suitable both for evaluating the origin of water that falls during extreme precipitation events and for establishing climatologies of moisture source-sink relationships. As far as oceanic sources are concerned, the important role of the subtropical northern Atlantic Ocean provides moisture for precipitation to the largest continental area, extending from Mexico to parts of Eurasia, and even to the South American continent during the Northern Hemisphere winter. In contrast, the influence of the southern Indian Ocean and North Pacific Ocean sources extends only over smaller continental areas. The South Pacific and the Indian Ocean represent the principal source of moisture for both Australia and Indonesia. Some landmasses only receive moisture from the evaporation that occurs in the same hemisphere (e.g., northern Europe and eastern North America), while others receive moisture from both hemispheres with large seasonal variations (e.g., northern South America). The monsoonal regimes in India, tropical Africa, and North America are provided with moisture from a large number of regions, highlighting the complexities of the global patterns of precipitation. Some very important contributions are also seen from relatively small areas of ocean, such as the Mediterranean Basin (important for Europe and North Africa) and the Red Sea, which provides water for a large area between the Gulf of Guinea and Indochina (summer) and between the African Great Lakes and Asia (winter). The geographical regions of Eurasia, North and South America, and Africa, and also the internationally important basins of the Mississippi, Amazon, Congo, and Yangtze Rivers, are also considered, as is the importance of terrestrial sources in monsoonal regimes. The role of atmospheric rivers, and particularly their relationship with extreme events, is discussed. Droughts can be caused by the reduced supply of water vapor from oceanic moisture source regions. Some of the implications of climate change for the hydrological cycle are also reviewed, including changes in water vapor concentrations, precipitation, soil moisture, and aridity. It is important to achieve a combined diagnosis of moisture sources using all available information, including stable water isotope measurements. A summary is given of the major research questions that remain unanswered, including (1) the lack of a full understanding of how moisture sources influence precipitation isotopes; (2) the stationarity of moisture sources over long periods; (3) the way in which possible changes in intensity (where evaporation exceeds precipitation to a greater of lesser degree), and the locations of the sources, (could) affect the distribution of continental precipitation in a changing climate; and (4) the role played by the main modes of climate variability, such as the North Atlantic Oscillation or the El Niño–Southern Oscillation, in the variability of the moisture source regions, as well as a full evaluation of the moisture transported by low-level jets and atmospheric rivers.Luis Gimeno would like to thank the Spanish Ministry of Science and FEDER for their partial funding of this research through the project MSM. A. Stohl was supported by the Norwegian Research Council within the framework of the WATER‐SIP project. The work of Ricardo Trigo was partially supported by the FCT (Portugal) through the ENAC project (PTDC/AAC-CLI/103567/2008).2013-05-0

    Sources of moisture for Central America based on a langrangian approach: variability, contributions to precipitation and transport mechanisms

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    The present work pressents a long term analysis of the sources of moisture for precipitation over Central America based on a Lagrangian analysis method. The importance of the water vapour in the climate system is presented in order to introduce the importance of the sources and sinks of moisture for understanding climate. The main global sources of moisture are presented to highlight the importance of studying regions like the Intra Americas Sea (IAS). The state of ghe art of the regional climate system is presented through a summary of the main features of regional climate, their importance and the sensitivity to the forcing of selected signals. The advantage of using Lagrangian approaches is ipresented followed by an introduction to the problem of the transport of moisture in the IAS region is presented with the main works that have been done. The objectives of this study and the main research activities are also given as a closure to the introductory part. The second part of this work is composed by the description of the methodology and datasets used for the study, followed by the long term analysis of the sources of moisture for Central America and their variability and information on the contributions to precipitation from the individual sources. The three dimensional structure of the moisture transport is explored, jointly with further discussions on the mechanisms that lead the moisture transport process. The role of the Caribbean Low Level Jet (CLLJ) as a moisture conveyor is analysed as well as its response to the vain variability modes affectin the IAS. A third and final part contains the summary of the main conclusions and results of this work closed by the proposal of the future research lines derived from the work herein presented
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