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12. Perception and confidence on weather forecasts among Spanish undergraduate students enrolled in different subjects related to physics

Author

Universidad de Alicante. Departamento de Física Aplicada, Gómez, Igor, Valor Micó, Enric, Molina-Palacios, Sergio, Niclòs, Raquel, Caselles, Vicente, Universidad de Alicante. Departamento de Física Aplicada, Gómez, Igor, Valor Micó, Enric, Molina-Palacios, Sergio, Niclòs, Raquel, and Caselles, Vicente

Abstract

The current study focuses on Spanish undergraduate students enrolled in Meteorology-related subjects that would make use of weather forecasts in their future professional careers. The main aim of this study is twofold. Firstly, to evaluate the students’ confidence in the current weather forecasts. Secondly, to analyze the students’ perception and understanding of uncertainty associated with weather-related forecasts. To address these issues, a Google Form questionnaire was developed. A total of 101 students participated in the corresponding survey during the academic year 2018-2019. Results show that students have a well-founded opinion and a fairly solid knowledge of weather forecasts, both regarding confidence and in relation to the trend found in the current weather forecasts towards less accurate predictions for larger lead times. The results found in the current study are in line with previous research conducted in different specific contexts and should be taken into account to implement different learning strategies in the classroom.

Published
2022

13. Confidence and Communication Preferences on Weather Forecasts among University Students in Spain

Author

Universidad de Alicante. Departamento de Física Aplicada, Universidad de Alicante. Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Gómez, Igor, Valor Micó, Enric, Molina-Palacios, Sergio, Niclòs, Raquel, Caselles, Vicente, Universidad de Alicante. Departamento de Física Aplicada, Universidad de Alicante. Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Gómez, Igor, Valor Micó, Enric, Molina-Palacios, Sergio, Niclòs, Raquel, and Caselles, Vicente

Abstract

Weather forecasts affect many persons’ lives and are used by the general public on a daily basis. However, they are not perfect, and there is an uncertainty associated with the current weather forecasts; users should be aware of this uncertainty. Previous research analyzes the perceptions, uses, and interpretations of uncertainty of Spanish undergraduate students. This study continues with this research line, but we investigate the degree of confidence and communication preferences of students enrolled in three meteorology-related subjects taught at two universities in Spain. We evaluated to what extent students trust in the current weather forecasts and analyzed how students are aware of the uncertainty associated with the forecasts considering different lead times. In addition, we assessed how students value the forecast of several weather elements as well as the students’ preferences for deterministic versus nondeterministic forecasts under two weather situations, with different degree of complexity in the forecast communication. A Google Form questionnaire was developed to address these issues. The survey was conducted in 2018/19, and 101 participants anonymously filled out the survey. Participants were enrolled in three different subjects taught in the degree in marine sciences at the University of Alicante and the degrees in environmental sciences and physics at the University of Valencia. Results show that students have a well-formed opinion of weather forecasts, both for confidence and in relation to the trend found in the current weather forecasts toward less accurate forecasts for larger lead times. For students’ preferences for deterministic versus nondeterministic forecasts, a significant majority of participants prefer weather forecasts that incorporate some uncertainty; a minority prefer single-valued (deterministic) forecasts. In comparing our results with those found in previous studies in different countries and contexts, similar outcomes are observ

Published
2022

16. Perception and confidence on weather forecasts among Spanish undergraduate students enrolled in different subjects related to physics

Author

Gómez, Igor, Valor, Enric, Molina, Sergio, Niclòs, Raquel, Caselles, Vicente, Universidad de Alicante. Departamento de Física Aplicada, and Grupo de Ingeniería y Riesgo Sísmico (GIRS)

Subjects
Physics students, Weather forecasts, Física de la Tierra, Uncertainty, Perception, Confidence
Abstract

[EN] The current study focuses on Spanish undergraduate students enrolled in Meteorology-related subjects that would make use of weather forecasts in their future professional careers. The main aim of this study is twofold. Firstly, to evaluate the students’ confidence in the current weather forecasts. Secondly, to analyze the students’ perception and understanding of uncertainty associated with weather-related forecasts. To address these issues, a Google Form questionnaire was developed. A total of 101 students participated in the corresponding survey during the academic year 2018-2019. Results show that students have a well-founded opinion and a fairly solid knowledge of weather forecasts, both regarding confidence and in relation to the trend found in the current weather forecasts towards less accurate predictions for larger lead times. The results found in the current study are in line with previous research conducted in different specific contexts and should be taken into account to implement different learning strategies in the classroom., This work has been funded by the Assistance Programmes of the University of Alicante ‘‘Programa de Redes-I3CE de calidad, innovación e investigación en docencia universitaria. Convocatoria 2018-19. Alicante: Instituto de Ciencias de la Educación (ICE) de la Universidad de Alicante. Ref: [4334].’’, “Programa de Redes-I3CE de calidad, innovación e investigación en docencia universitaria. Convocatoria 2019-20. Alicante: Instituto de Ciencias de la Educación (ICE) de la Universidad de Alicante. Ref: [4669]”, and ‘‘Programa de Redes-I3CE de calidad, innovación e investigación en docencia universitaria. Convocatoria 2020-21. Alicante: Instituto de Ciencias de la Educación (ICE) de la Universidad de Alicante. Ref: [5150].’’

Published
2022

18. Espectroradiometría de campo del visible al infrarrojo térmico de muestras con características espectrales singulares

Author

Mira Sarrió, Maria, Niclòs, Raquel, Valor, Enric, Pons, Xavier, Cea López, Cristina, García-Santos, Vicente, Caselles, Diego, and Caselles, Vicente

Subjects
Espectroscopía, Sal, Calcita, USB2000+, FTIR, Reflectividad y emisividad espectral, Medidas de campo, Yeso, Cuarzo
Abstract

La calibración de sensores a bordo de satélite requiere medidas espectrales de campo simultáneas al paso del satélite. El objetivo de este trabajo es determinar y validar el protocolo óptimo para medir en el campo espectros de reflectividad (del visible al infrarrojo cercano) y emisividad (en el infrarrojo térmico) de muestras con características espectrales singulares (calcita, cuarzo, yeso y sal). Los espectrorradiómetros analizados son el Ocean Optics USB2000+ (200-1100 nm) y el

Published
2021

22. Percepción y valoración del alumnado en relación a la comunicación de la incertidumbre asociada a las predicciones meteorológicas

Author

Gómez, Igor, Molina-Palacios, Sergio, Valor Micó, Enric, Soler Llorens, Juan Luis, Niclòs, Raquel, Caselles, Vicente, Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, and Grupo de Ingeniería y Riesgo Sísmico (GIRS)

Subjects
Incertidumbre, Estudiantes de Meteorología, Física de la Tierra, Predicciones meteorológicas, Modelos numéricos, Percepción y valoración
Abstract

El uso de resultados de modelos numéricos como recurso para el estudio de conceptos complejos en asignaturas relacionadas con la Meteorología está ampliamente extendido. En concreto, en lo referente a las predicciones meteorológicas. El propósito del presente estudio es explorar la confianza que tiene el alumnado matriculado en este tipo de áreas del conocimiento en dichas predicciones. Para ello, se ha utilizado un enfoque cuantitativo y método no experimental a través de una encuesta. Se recoge así información relacionada con el medio de comunicación preferente utilizado por el alumnado para obtener este tipo de previsiones, así como información relacionada con la percepción y valoración de los estudiantes de las predicciones meteorológicas así como de la incertidumbre asociada. La muestra se compone de 157 individuos pertenecientes a las universidades de Alicante (n = 73) y Valencia (n = 84). Los resultados indican que el alumnado solo experimenta previsiones incorrectas algunas veces o incluso raramente y muestra una idea clara de la incertidumbre. Estos resultados están de acuerdo con estudios simulares llevados a cabo en otros países.

Published
2019

23. Percepción y valoración del alumnado en relación a la comunicación de la incertidumbre asociada a las predicciones meteorológicas

Author

Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Molina-Palacios, Sergio, Valor Micó, Enric, Soler Llorens, Juan Luis, Niclòs, Raquel, Caselles, Vicente, Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Molina-Palacios, Sergio, Valor Micó, Enric, Soler Llorens, Juan Luis, Niclòs, Raquel, and Caselles, Vicente

Abstract

El uso de resultados de modelos numéricos como recurso para el estudio de conceptos complejos en asignaturas relacionadas con la Meteorología está ampliamente extendido. En concreto, en lo referente a las predicciones meteorológicas. El propósito del presente estudio es explorar la confianza que tiene el alumnado matriculado en este tipo de áreas del conocimiento en dichas predicciones. Para ello, se ha utilizado un enfoque cuantitativo y método no experimental a través de una encuesta. Se recoge así información relacionada con el medio de comunicación preferente utilizado por el alumnado para obtener este tipo de previsiones, así como información relacionada con la percepción y valoración de los estudiantes de las predicciones meteorológicas así como de la incertidumbre asociada. La muestra se compone de 157 individuos pertenecientes a las universidades de Alicante (n = 73) y Valencia (n = 84). Los resultados indican que el alumnado solo experimenta previsiones incorrectas algunas veces o incluso raramente y muestra una idea clara de la incertidumbre. Estos resultados están de acuerdo con estudios simulares llevados a cabo en otros países.

Published
2019

24. Simulation of extreme heat events over the Valencia coastal region: Sensitivity to initial conditions and boundary layer parameterizations

Author

Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Niclòs, Raquel, Estrela, María J., Caselles, Vicente, Barberà, María Jesús, Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Niclòs, Raquel, Estrela, María J., Caselles, Vicente, and Barberà, María Jesús

Abstract

The Valencia coastal region (Western Mediterranean) is especially sensitive to extreme heat events, where they are really common. However, due to its geophysical characteristics and climatic conditions, the incidence of high and extreme temperatures may still be modulated over this area by means of sea breeze circulations, defining a Sea Breeze Convergence Zone (SBCZ) due to the meet and interaction of these mesoscale conditions and Western synoptic-scale wind regimes. A proper definition of this convergence zone is of significant importance over the study area for the simulation and forecast of intense-heat meteorological events. This study analyses a week period in August 2010 over this area, which alternates the presence of meteorological conditions prone to high and extreme temperatures with sea breeze conditions that temper these extreme temperatures. The simulations have been performed using the mesoscale model Regional Atmospheric Modeling System (RAMS). The analysis focuses on the ability of different initial conditions and technical features and two widely used planetary boundary layer parameterizations to forecast and reproduce the observed high and extreme temperatures, as well as to properly capture the main associated atmospheric patterns. It has been found that an increased horizontal resolution in the initial atmospheric fields produces a better representation of the regional and local wind flows simulated by the mesoscale model, leading to an accurate characterization of the temperature fields when these wind circulations dominate over the area of study. However, no significant differences are obtained within the intense-heat situations, associated with atmospheric synoptic-scale forcings. Regarding PBL parameterizations, the local PBL scheme tends to underestimate the daytime temperatures, while the non-local scheme produces higher temperatures than the local scheme, skilfully reproducing the observations. Additionally, the non-local scheme overesti

Published
2019

30. Impact of Initial Soil Temperature Derived from Remote Sensing and Numerical Weather Prediction Datasets on the Simulation of Extreme Heat Events

Author

Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Caselles, Vicente, Estrela, María J., Niclòs, Raquel, Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Gómez, Igor, Caselles, Vicente, Estrela, María J., and Niclòs, Raquel

Abstract

Extreme heat weather events have received increasing attention and has become of special importance as they can remarkably affect sectors as diverse as public health, energy consumption, water resources, natural biodiversity and agricultural production. In this regard, summer temperatures have become a parameter of essential interest under a framework of a hypothetical increase in the number of intense-heat conditions. Thus, their forecast is a crucial aspect bearing in mind a mitigation of the effects and impacts that these intense-heat situations could produce. The current work tries to reach a better understanding of these sorts of situations that are really common over the Western Mediterranean coast. An extreme heat episode that took place in the Valencia Region in July 2009 is analysed, based on the simulations performed with the Regional Atmospheric Modeling System (RAMS). This event recorded maximum temperatures exceeding 40 °C amply extended over the region besides reaching minimum temperatures up to 25.92 °C. We examine the role of improved skin and soil temperature (ST) initial conditions in the forecast results by means of different modelling and satellite-derived products. The influence of incorporating the Land Surface Temperature (LST) into RAMS is not found to produce a meaningful impact on the simulation results, independently of the resolution of the dataset used in the initial conditions of the model. In contrast, the introduction of the ST in lower levels, not only the skin temperature, has a more marked decisive effect in the simulation. Additionally, we have evaluated the influence of increasing the number of soil levels to spread deeper underground. This sensitivity experiment has revealed that more soil levels do not produce any meaningful impact on the simulation compared to the original one. In any case, RAMS is able to properly capture the observed patterns in those cases where a Western advection is widely extended over the area of study.

Published
2016

31. Evaluation of landsat-8 thermal bands to monitor land surface temperature

Author

Niclòs, Raquel, Sánchez Tomás, Juan M., Valiente, José A., Barberá Bisbal, Maria Jesús, Caselles, Diego, Coll, César, and Caselles, Vicente

Subjects
Calibración, Calibration, Temperatura de la superficie terrestre, Thermal infrared, Land surface temperature, Infrarrojo térmico
Abstract

Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014. [ES]El nuevo Thermal Infrared Sensor (TIRS) a bordo del Landsat-8 (L8) dispone de dos bandas térmicas, 10 (11.60-11.19 μm) y 11 (11.50-12.51 μm), con una resolución espacial de 100m, con el fin de proporcionar temperaturas de la superficie terrestre (LST) de una manera más precisa que su predecesor Landsat-7 ETM+. El L8 fue lanzado en febrero de 2013, comenzando su adquisición operativa a mediados de abril. Los primeros estudios realizados por el equipo de calibración de L8 mostraron errores sistemáticos significativos para el TIRS, y en febrero de 2014 el archivo de imágenes L8 TIRS fue reprocesado para corregir dichos errores. En este estudio, con el fin de comprobar la calibración del L8 TIRS, realizamos medidas de campo en una zona llana y térmicamente homogénea dedicada al cultivo del arroz. A partir de estas medidas de LST simulamos las radiancias y temperaturas de brillo a nivel del satélite y las comparamos con los datos TIRS. Tal y como apuntaba el equipo de L8, nuestros resultados muestran una sobreestimación para la banda 11. Sin embargo, el recalibrado aplicado por dicho equipo para ambas bandas ha resultado no ser satisfactorio en nuestra zona experimental, ya que proponen sustraer errores sistemáticos mayores a los requeridos. [EN]The new Landsat-8 (L8) Thermal Infrared Sensor (TIRS) has two thermal bands, 10 (11.60- 11.19 μm) and 11 (11.50-12.51 μm) at 100-m spatial resolution, aimed to provide more accurate Land Surface Temperatures (LST) than Landsat-7 ETM+. L8 was launched on February 2013, and operational acquisitions started in middle April 2013. The first studies by the L8 Calibration Team showed significant TIRS temperature offsets, and in February 2014 the L8 TIRS archive was reprocessed to remove these offsets. In this study, ground LST measurements were performed in a flat and thermally homogeneous area of rice-crop fields for checking the calibration of the L8 TIRS bands. At-sensor radiances and brightness temperatures were simulated from ground-measured LSTs and compared with TIRS values. A significant overestimation was observed for band 11, in agreement with the L8 Calibration Team results. However, their recalibration was shown unsatisfactory in our test site for both bands, since they proposed subtracting higher offsets than required. This study was supported by the Spanish Ministerio de Economía y Competitividad (projects CGL2010-16364, CGL2010-17577/CLI, CGL2011-13579-E, CGL2011-30433 and GRACCIE Consolider-Ingenio 2010; and Dr. Niclòs "Ramón y Cajal" Research Contract) and Generalitat Valenciana (PROMETEO/2009/006 and PROMETEO/2009/086 projects).

Published
2014

32. Seguimiento del balance de energía en superficie a través de la futur misión HyspIRI

Author

Sánchez Tomás, Juan M., Caselles, Vicente, García Santos, Vicente, French, Andrew N., Niclòs, Raquel, and Doña, Carolina

Subjects
Evapotranspiration, Multispectral, Multiespectral, Emissivity, Temperature, Emisividad, Temperatura, HyspIRI, Evapotranspiración
Abstract

Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014. [ES]La estimación operativa y a escala global del balance de energía en superficie requiere de datos de temperatura desde satélite con alta frecuencia y resolución espacial. Sus 8 bandas en el térmico, los 60 m de tamaño de píxel y los 5 días de revisita, convierten a la misión HyspIRI en el futuro de la teledetección térmica multiespectral. En este trabajo se han simulado productos HyspIRI de flujos energéticos a partir de vuelos MASTER, de muy alta resolución espacial, sobre las reservas experimentales de Jornada y Sevilleta, situadas en el suroeste de EEUU. Para ello se ha utilizado un modelo de balance de energía de dos fuentes, combinado con datos meteorológicos registrados en la zona. Los resultados muestran la estabilidad del modelo aplicado a las imágenes simuladas HyspIRI, y permiten hacer un análisis del efecto de la pérdida de resolución espacial sobre la variabilidad de los flujos energéticos en zonas áridas. [EN]Frequent and high resolution remote sensing temperature data are needed for global scale, operational estimation of the surface energy balance. Its 8 thermal bands, 60-m pixel size and 5-day revisit time make the HyspIRI mission the future of the multispectral thermal remote sensing. In this work HyspIRI products of surface energy fluxes were simulated from very high spatial resolution MASTER flights, over the Jornada and Sevilleta experimental ranges, southwest USA. A two-source energy balance model, together with meteorological data, were used in this work. Results show the stability of the model when applied to simulated HyspIRI images, and allow performing an analysis of the effect of the spatial resolution degradation on the surface variability in arid areas in terms of energy fluxes. Los autores desean expresar su agradecimiento por la financiación recibida a NASA (10-HYSPIRI1 0-13), al Ministerio de Economía y Competitividad (CGL2010-17577/CLI) y a la Generalitat Valenciana (PROMETEO/2009/086).

Published
2014

33. Spatial and temporal patterns of the stability and humidity terms in the Haines index to improve the estimate of forest fire risk in the Valencia region of Spain

Author

Barberá Bisbal, Maria Jesús, Estrela Navarro, María José, Niclòs, Raquel, and Valiente, José A.

Subjects
Climatology, Estabilidad, Haines Index, Humidity, Incendios forestales dominados por columna, Índice de Haines, Plume-dominated fires
Abstract

Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014. [EN]The assessment of risk index in the propagation and evolution of a hypothetical forest fire is commonly based on stability and moisture content at different atmospheric levels. The Haines Index combines these terms to determine the environmental potential for wildfire growth. In this study the environmental stability and humidity associated with the lower atmospheric layers in the Western Mediterranean Basin are investigated by analysing Haines Index calculations over a 29 year period. [ES]La evaluación del índice de riesgo en la propagación y evolución de un hipotético incendio forestal está basada habitualmente en la estabilidad y el contenido de humedad en los diferentes niveles atmosféricos. El Índice de Haines combina estos términos para determinar el potencial ambiental en el desarrollo de un incendio forestal. En este estudio la estabilidad ambiental y la humedad asociada a las capas atmosféricas más bajas de la cuenca del Mediterráneo occidental se investigan mediante el análisis del cálculo del Índice de Haines durante un período de 29 años. We thank NCEP/NCAR for supplying the data necessary for this study. This study was supported by the Spanish Ministry of Innovation and Science (projects CGL2010-16364, CGL2011-30433-C02 and GRACCIE Consolider-Ingeio 2010; and Dr. Niclòs "Ramón y Cajal"Research Contract) and Generalitat Valenciana (Prometeo/2009/006 FEEDBACKS project). The Instituto Universitario CEAM-UMH is partly supported by the Generalitat.

Published
2014

37. A Lookup Table-Based Method for Estimating Sea Surface Hemispherical Broadband Emissivity Values (8–13.5 μm).

Author

Jie Cheng, Xiaolong Cheng, Shunlin Liang, Niclòs, Raquel, Aixiu Nie, and Qiang Liu

Subjects
OCEAN bottom, EMISSIVITY, REFRACTIVE index, WIND speed, HEMISPHERICAL photography
Abstract

Sea surface hemispherical broadband emissivity (BBE, 8–13.5 μm) is a vital parameter for calculating surface radiation budgets. Such data are currently unavailable. This paper proposes a lookup table-based method for retrieving sea surface hemispherical BBE values. The physically-based sea surface emissivity model of Wu and Smith, together with the optimal refractive index, were used to generate hemispherical BBE values under wind speeds ranging from zero to 50 m/s. A lookup table of hemispherical BBE values as a function of wind speed was established and used to retrieve sea surface hemispherical BBE values under foam-free conditions. The accuracy of the estimates of hemispherical BBE was 0.003, given a wind speed of zero. The foam effect was explicitly considered. After incorporating the foam effect, hemispherical BBE was expressed as a linear function of the hemispherical BBE values of sea water and foam, weighted by the fraction of foam coverage. With this method, we have produced an hourly sea surface hemispherical BBE product with a resolution of 10 km and global coverage that covers the period from 2003 to 2005, using wind speed data from Modern-Era Retrospective analysis for Research and Applications (MERRA)-2. [ABSTRACT FROM AUTHOR]

Published
2017
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39. Impact of Initial Soil Temperature Derived from Remote Sensing and NumericalWeather Prediction Datasets on the Simulation of Extreme Heat Events.

Author

Gómez, Igor, Caselles, Vicente, Estrela, María José, and Niclòs, Raquel

Subjects
SOIL temperature, REMOTE sensing, WEATHER forecasting, AGRICULTURAL productivity & the environment, LAND surface temperature
Abstract

Extreme heat weather events have received increasing attention and has become of special importance as they can remarkably affect sectors as diverse as public health, energy consumption, water resources, natural biodiversity and agricultural production. In this regard, summer temperatures have become a parameter of essential interest under a framework of a hypothetical increase in the number of intense-heat conditions. Thus, their forecast is a crucial aspect bearing in mind a mitigation of the effects and impacts that these intense-heat situations could produce. The current work tries to reach a better understanding of these sorts of situations that are really common over theWestern Mediterranean coast. An extreme heat episode that took place in the Valencia Region in July 2009 is analysed, based on the simulations performed with the Regional Atmospheric Modeling System (RAMS). This event recorded maximum temperatures exceeding 40 °C amply extended over the region besides reaching minimum temperatures up to 25.92 °C. We examine the role of improved skin and soil temperature (ST) initial conditions in the forecast results by means of different modelling and satellite-derived products. The influence of incorporating the Land Surface Temperature (LST) into RAMS is not found to produce a meaningful impact on the simulation results, independently of the resolution of the dataset used in the initial conditions of the model. In contrast, the introduction of the ST in lower levels, not only the skin temperature, has a more marked decisive effect in the simulation. Additionally, we have evaluated the influence of increasing the number of soil levels to spread deeper underground. This sensitivity experiment has revealed that more soil levels do not produce any meaningful impact on the simulation compared to the original one. In any case, RAMS is able to properly capture the observed patterns in those cases where a Western advection is widely extended over the area of study. This region's variability in orography and in distances to the sea promotes the development of sea-breeze circulations, thus producing a convergence of two opposite wind flows, a Western synoptic advection and a sea-breeze circulation. As a result, the RAMS skill in those cases where a sea breeze is well developed depends on the proper location of the boundary and convergence lines of these two flows. [ABSTRACT FROM AUTHOR]

Published
2016
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45. Climatology of the stability and humidity terms in the Haines Index to improve the estimate of forest fire risk in the Western Mediterranean Basin (Valencia region, Spain).

Author

Barberà, Maria J., Niclòs, Raquel, Estrela, Maria J., and Valiente, José A.

Subjects
*CLIMATOLOGY, *HUMIDITY, *FOREST fires, *METEOROLOGY, *ATMOSPHERIC boundary layer, *ATMOSPHERIC circulation
Abstract

ABSTRACT The stability and moisture content of the different atmospheric levels are commonly used to assess the risk index in the propagation and evolution of a hypothetical forest fire. The Haines Index (HI) combines these terms to determine the environmental potential for wildfire growth. In this paper the environmental stability and humidity associated with the lower atmospheric layers in the Western Mediterranean Basin are investigated by analysing HI calculations over a 29-year period. The HI climatology can be applied to the study of plume-dominated forest fires. These fires tend to present very erratic propagation behaviour and create highly dangerous situations for fire brigades. Thus the knowledge of the typical index values and the meteorological situations that generate them could be extremely useful for minimizing the fire risk and planning specific fire-fighting activities. In this study we carry out a spatial and temporal analysis of the Index and its terms in the Valencia region on the basis of NCEP/ NCAR reanalysis data from 1980 to 2008, obtaining a detailed climatological analysis of the HI in the Valencia region for each variant of elevation, which can be used as a reference tool. Moreover, using NCEP reanalysis maps at 500 and 850 hPa, we also perform a daily synoptic analysis for the studied period which is finally associated to the different values that the Index can show in this area. As a result three dominant synoptic weather situations have been defined in this region: continental, maritime and convective. A direct proportionality has been found between increases in the HI and convective situations. [ABSTRACT FROM AUTHOR]

Published
2015
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50. Soil Moisture Effect on Thermal Infrared (8-13-µm) Emissivity.

Author

Mira, Maria, Valor, Enric, Caselles, Vicente, Rubio, Eva, Coll, César, Galve, Joan M., Niclòs, Raquel, Sánchez, Juan M., and Boluda, Rafael

Subjects
EMISSIONS (Air pollution), SOIL moisture, REMOTE sensing, SOILS, RADIOMETERS
Abstract

Thermal infrared (TIR) emissivities of soils with different textures were measured for several soil moisture (SM) contents under controlled conditions using the Box method and a high-precision multichannel TIR radiometer. The results showed a common increase of emissivity with SM at water contents lower than the field capacity. However, this dependence is negligible for higher water contents. The highest emissivity variations were observed in sandy soils, particularly in the 8-9-µm range due to water adhering to soil grains and decreasing the reflectance in the 8-9-µm quartz doublet region. Thus, in order to model the emissivity dependence on soil water content, different approaches were studied according to the a priori soil information. Soil-specific relationships were provided for each soil texture and different spectral bands between 8 and 13 µm, with determination coefficients up to 0.99, and standard estimation errors in emissivity lower than ±0.014. When considering a general relationship for all soil types, standard estimation errors up to ±0.03 were obtained. However, if other soil properties (i.e., organic matter, quartz, and carbonate contents) were considered, along with soil water content, the general relationship predicted TIR emissivities with a standard estimation error of less than ±0.008. Furthermore, the study showed the possibility of retrieving SM from TIR emissivities with a standard estimation error of about ±0.08 m³ * m-3. [ABSTRACT FROM AUTHOR]

Published
2010
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