Person: Losada Doval, Teresa
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First Name
Teresa
Last Name
Losada Doval
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Física de la Tierra y Astrofísica
Area
Física de la Tierra
Identifiers
18 results
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Now showing 1 - 10 of 18
Item Relationships among Intermodel Spread and Biases in Tropical Atlantic Sea Surface Temperatures(Journal of Climate, 2019) Mohino Harris, Elsa; Rodríguez De Fonseca, María Belén; Mechoso, C. Roberto; Losada Doval, Teresa; Polo Sánchez, IreneState-of-the-art general circulation models show important systematic errors in their simulation of sea surface temperatures (SST), especially in the tropical Atlantic. In this work the spread in the simulation of climatological SST in the tropical Atlantic by 24 CMIP5 models is examined, and its relationship with the mean systematic biases in the region is explored. The modes of intermodel variability are estimated by applying principal component (PC) analysis to the SSTs in the region 70ºW–20ºE, 20ºS–20ºN. The intermodel variability is approximately explained by the first three modes. The first mode is related to warmer SSTs in the basin, shows worldwide connections with same-signed loads over most of the tropics, and is connected with lower low cloud cover over the eastern parts of the subtropical oceans. The second mode is restricted to the Atlantic, where it shows negative and positive loads to the north and south of the equator, respectively, and is connected to a too weak Atlantic meridional overturning circulation (AMOC). The third mode is related to the double intertropical convergence zone bias in the Pacific and to an interhemispheric asymmetry in the net radiation at the top of the atmosphere. The structure of the second mode is closer to the mean bias than that of the others in the tropical Atlantic, suggesting that model difficulties with the AMOC contribute to the regional biases. State-of-the-art general circulation models show important systematic errors in their simulation of sea surface tem- peratures (SST), especially in the tropical Atlantic. In this work the spread in the simulation of climatological SST in the tropical Atlantic by 24 CMIP5 models is examined, and its relationship with the mean systematic biases in the region is explored. The modes of intermodel variability are estimated by applying principal component (PC) analysis to the SSTs in the region 708W–208E, 208S–208N. The intermodel variability is approximately explained by the first three modes. The first mode is related to warmer SSTs in the basin, shows worldwide connections with same-signed loads over most of the tropics, and is connected with lower low cloud cover over the eastern parts of the subtropical oceans. The second mode is restricted to the Atlantic, where it shows negative and positive loads to the north and south of the equator, respectively, and is connected to a too weak Atlantic meridional overturning circulation (AMOC). The third mode is related to the double intertropical convergence zone bias in the Pacific and to an interhemispheric asymmetry in the net radiation at the top of the atmosphere. The structure of the second mode is closer to the mean bias than that of the others in the tropical Atlantic, suggesting that model difficulties with the AMOC contribute to the regional biases.Item Tropical atmospheric response of Atlantic Niños to changes in the ocean background state(2023) Svendsen, Lea; Rodríguez De Fonseca, María Belén; Mohino Harris, Elsa; Crespo, Lander; Losada Doval, TeresaSince the 1970s, Atlantic Ninos during boreal summer have been linked to Pacific La Ninas the following winter. Earlier studies have explained the appearance of the Atlantic-Pacific teleconnection with changing Atlantic Nino configurations. Here we find that the non-stationarity of this teleconnection can also be explained by changes in the ocean background state, without changing the Atlantic Nino configuration. Experiments with different atmospheric general circulation models are performed where the same Atlantic Nino pattern is prescribed to different global ocean background states. The 1975-1985 global mean sea surface temperature forces a Walker Circulation response and low-level convergence over the Maritime Continent, increasing the chance of triggering a La Nina-like event in the Pacific. These results suggest that ENSO-predictions could be improved in certain periods by considering tropical Atlantic variability. The Atlantic Nino is the main climate variability phenomenon in the equatorial Atlantic and has a strong influence on local and remote climate. Since the 1970s, warm Atlantic Nino events in June-August have been linked to cool La Nina events developing in the equatorial Pacific the following December-February. The appearance of this Atlantic-Pacific link has been explained by changes in the temperature pattern of Atlantic Ninos but, so far, no study has analyzed the role of mean state changes. In this study we demonstrate the contribution of changes in the mean background surface temperatures of the global oceans to the appearance of this Atlantic-Pacific link. These results imply that under certain global ocean background conditions, we should use information about the Atlantic Nino to improve seasonal forecasts of El Nino and La Nina events. An Atlantic Nino in summer can produce atmospheric conditions of a La Nina-like event in the Pacific under certain ocean background statesThe ocean background state is of similar importance as the Atlantic Nino pattern for modifying the Atlantic Nino-Pacific teleconnectionAn Atlantic Nino intensifies easterly wind anomalies over the western equatorial Pacific when the Pacific has a warmer background state- Project number: PIMCD244/23-24
Item Cambiando el rol del profesorado en el aula de transmisor a facilitador(2024) De La Cámara Illescas, Álvaro; Calvo Fernández, Natalia; Ábalos Álvarez, Marta; Durán Montejano, Luis; García Herrera, Ricardo Francisco; González Rouco, Jesús Fidel; Losada Doval, Teresa; Montoya Redondo, María Luisa; Negredo Moreno, Ana María; Pavón Carrasco, Francisco Javier; Polo Sánchez, Irene; Rodríguez De Fonseca, María Belén; Sastre Marugán, Mariano; Yagüe Anguis, Carlos; Zurita Gotor, Pablo; De La Cámara Illescas, ÁlvaroEste proyecto propone un cambio del rol del docente en el aula de transmisor a facilitador. Para ello, se apuesta por implantar metodologías que favorezcan el aprendizaje cooperativo en el aula y potencien el desarrollo de competencias transversales. Item A shift in the wind regime of the southern end of the Canary upwelling system at the turn of the 20th century(Journal of geophysical research-oceans, 2021) Gallego, D.; García Herrera, Ricardo Francisco; Losada Doval, Teresa; Mohino Harris, Elsa; Rodríguez De Fonseca, María BelénIn this study, we make use of historical wind direction observations to assemble an instrumental upwelling index (DUI) at the southern end of the Canary Current Upwelling System. The DUI covers the period between 1825 and 2014 and, unlike other upwelling indices, it does not rely neither in wind speed nor in reanalyzed data. In this sense, the DUI can be regarded as an instrumental index. Additionally, it avoids the suspected bias toward increasing wind speed of historical wind observations documented in previous research. Our results indicate that the frequency of the alongshore winds at the west coast of Africa between 10°N and 20°N measured by the DUI is significantly related with the wind stress and therefore the upwelling intensity in this region. The DUI presents a significant variability both at interannual and decadal timescales. We have not found any significant trend for the 20th century. However, when the entire length of the series is considered, a large shift toward more frequent alongshore winds is evidenced as a result of several decade-long fluctuations which took place between the late 19th century and the beginning of the 20th century. This fact would imply that a significant change in the upwelling intensity at the southern end of the Canary Current Upwelling System should have occurred at the turn of the 20th century.Item Changes in interannual tropical Atlantic-Pacific basin interactions modulated by a South Atlantic cooling(Journal of climate, 2022) Losada Doval, Teresa; Rodríguez De Fonseca, María Belén; Mechoso, Roberto; Mohino Harris, Elsa; Castaño-Tierno, AntonioAlthough tropical interbasin interactions at interannual time scales are presently receiving much attention, their controlling factors and variations on longer time scales are under debate. Tropical convection plays a crucial role in the occurrence and nonstationarity of them. In this paper, we investigate the dependence of interannual tropical AtlanticPacific basin interactions on convection-related features of the tropical oceans’ climatology, especially the ITCZ position. Wecontrast a CGCM control simulation with an experiment in which tropical convection is modified by an artificial perturbation outside the tropics that reduces the incident shortwave radiation in a region of the South Atlantic. Based on previous work, this modification is expected to shift in latitude the climatological position of the simulated ITCZ. The experiment shows altered Walker circulations, stronger interannual variability over the tropical oceans, a westward extension of the Atlantic Ni˜no pattern and of convection, and shallower thermocline in the Pacific, making the basin more sensitive to both local and remote perturbations. As a consequence, the experiment shows enhanced interannual Atlantic–Pacificbasin interactions at the equator, and weaker teleconnections between the north tropical Atlantic and the equatorial Pacific. The latter seems to occur because the impact of the warm Atlantic SST anomalies is offset by the presence of warm SST anomalies in El Ni˜no region. Despite the uncertainties raised because the simulations are relatively short, we conclude that this work presents a potential explanation for the long-term changes in the tropical basin interactions and offers a novel and useful methodology for their analysis.- Project number: 151
Item Meteolab como herramienta educativa de Meteorología en el Aula(2021) Rodríguez De Fonseca, María Belén; Ábalos Álvarez, Marta; Alvarez Solas, Jorge; Ayarzagüena Porras, Blanca; Benito Barca, Samuel; Calvo Fernández, Natalia; de la Cámara Illescas, Alvaro; Durán Montejano, Luis; García Herrena, Ricardo; Garrido Pérez, José Manuel; Gómara Cardalliaguet, Iñigo; Losada Doval, Teresa; Mohino Harris, Elsa; Montoya Redondo, Marisa Luisa; Ordoñez García, Carlos; Polo Sánchez, Irene; Robinson, Alexander James; Sastre Marugán, Mariano; Serrano Mendoza, Encarnación; Yagüe Anguis, Carlos; Zurita Gotor, Pablo; García Burgos, Marina; González Alemán, Juan Jesús; González Barras, Rosa María; González Rouco, Jesús Fidel; Martín Gómez, Verónica; Maqueda Burgos, GregorioEl Presente proyecto es una continuación de proyectos anteriores dentro de la plataforma de divulgación Meteolab. Meteolab es un proyecto de divulgación de Meteorología y Clima que tiene su origen en 2002, cuando se comenzaron a diseñar experimentos de bajo coste con materiales caseros para la Semana de la Ciencia de la Comunidad de Madrid (CAM). Con los años, se generó un conocimiento que se materializó en 2010 con la concesión de un Proyecto de Innovación Educativa (PIE) financiado por la Universidad Complutense de Madrid (UCM), dirigido por Belén Rodríguez de Fonseca. Gracias a este primer proyecto en el que trabajaron muchos profesores y alumnos de ciencias de la atmósfera, se gestó un portal web (meteolab.fis.ucm.es) en el que los experimentos se explicaban y se grababan para impulsar su difusión. Más adelante, en un segundo proyecto de Innovación Educativa, dirigido por la profesora Maria Luisa Montoya, los contenidos fueron traducidos al inglés. En concreto, los experimentos que componen Meteolab tienen como principal objetivo entender los principios y variables que determinan el comportamiento de las masas de aire en la atmósfera y de agua en el océano. La idea consiste en visualizar con experimentos sencillos las leyes físicas que gobiernan la atmósfera y el océano: movimientos horizontales y verticales, cambios de estado, mezcla y equilibrio, así como la interacción entre componentes. Se persigue observar los procesos meteorológicos familiares, como son la formación de una nube, los tornados, la convección, la formación de borrascas o la lluvia, entendiendo los procesos físicos que los producen. Finalmente, Meteolab permite también visualizar fenómenos climáticos como el efecto invernadero, el fenómeno de El Niño, el deshielo del Ártico, la influencia de los volcanes en el clima o la subida del nivel del mar. Existe un catálogo de experimentos, la mayoría de los cuales pueden consultarse a través del portal meteolab.fis.ucm.es, encontrándose todos ellos físicamente localizados en el Laboratorio Elvira Zurita de la Facultad de Ciencias Físicas. Tras la experiencia acumulada durante los 18 años de existencia de Meteolab, en los que se han adecuado las explicaciones de los experimentos a distintos niveles de dificultad (infantil, primaria, secundaria, bachillerato y Universidad de mayores), se ha sugerido la idoneidad de adaptar los contenidos a los estudiantes del Grado en Física y del Máster en Meteorología y Geofísica de la UCM. Así, por ejemplo, cuando se explica la formación de una nube, se puede ir complicando el discurso dependiendo de los diferentes ciclos de la enseñanza. De esta manera, para un nivel de escuela primaria uno sólo tiene que explicar que el aire se enfría al ascender, y al enfriarse se forman gotas de agua que forman las nubes. Al llegar a secundaria, los estudiantes aprenden el concepto de presión atmosférica y la relación entre la temperatura, la presión y el volumen de una parcela de aire. Más adelante, en el Grado en Física, se estudia la tensión de vapor, la expansión adiabática y la existencia de núcleos de condensación. Finalmente, en el Máster en Meteorología se aprenden los distintos procesos de nucleación y tipos de nubes. Todos estos conceptos van complicando la explicación, por lo que un mismo experimento puede explicarse tanto en una escuela infantil como en una Universidad. Es por ello, que, aprovechando la plataforma de divulgación Meteolab, hemos decidido dar un paso adelante y adaptar y ampliar los contenidos de Meteolab, para así poder integrarlos en los currícula del Grado en Física y del Máster en Meteorología y Geofísica de la UCM. Con todo ello, los objetivos del presente proyecto han sido: -Implementar los experimentos de Meteolab en el Aula, tanto en las asignaturas de Grado como en las de Máster. -Adaptar los contenidos existentes del portal web Meteolab (meteolab.fis.ucm.es) a las asignaturas relacionadas con Meteorología del Grado en Física y del Máster en Meteorología y Geofísica, con el fin de visualizar procesos físicos que se explican en el aula. -Añadir a Meteolab nuevos contenidos en relación con la dinámica de la atmósfera y el cambio climático. -Evaluar la mejora de la comprensión por parte del alumnado de los procesos que tienen lugar principalmente en la atmósfera y el océano, y su relación con el clima y su variabilidad. Item Impact of dynamical regionalization on precipitation biases and teleconnections over West Africa(Climate dynamics, 2018) Gómara Cardalliaguet, Íñigo; Mohino Harris, Elsa; Losada Doval, Teresa; Domínguez, Marta; Suárez Moreno, Roberto; Rodríguez De Fonseca, María BelénWest African societies are highly dependent on the West African Monsoon (WAM). Thus, a correct representation of the WAM in climate models is of paramount importance. In this article, the ability of 8 CMIP5 historical General Circulation Models (GCMs) and 4 CORDEX-Africa Regional Climate Models (RCMs) to characterize the WAM dynamics and variability is assessed for the period July-August-September 1979-2004. Simulations are compared with observations. Uncertainties in RCM performance and lateral boundary conditions are assessed individually. Results show that both GCMs and RCMs have trouble to simulate the northward migration of the Intertropical Convergence Zone in boreal summer. The greatest bias improvements are obtained after regionalization of the most inaccurate GCM simulations. To assess WAM variability, a Maximum Covariance Analysis is performed between Sea Surface Temperature and precipitation anomalies in observations, GCM and RCM simulations. The assessed variability patterns are: El Nio-Southern Oscillation (ENSO); the eastern Mediterranean (MED); and the Atlantic Equatorial Mode (EM). Evidence is given that regionalization of the ENSO-WAM teleconnection does not provide any added value. Unlike GCMs, RCMs are unable to precisely represent the ENSO impact on air subsidence over West Africa. Contrastingly, the simulation of the MED-WAM teleconnection is improved after regionalization. Humidity advection and convergence over the Sahel area are better simulated by RCMs. Finally, no robust conclusions can be determined for the EM-WAM teleconnection, which cannot be isolated for the 1979-2004 period. The novel results in this article will help to select the most appropriate RCM simulations to study WAM teleconnections.Item Impact of equatorial Atlantic variability on ENSO predictive skill(Nature communications, 2021) Exarchou, Eleftheria; Ortega, Pablo; Rodríguez De Fonseca, María Belén; Losada Doval, Teresa; Polo Sánchez, Irene; Prodhomme, CloéEl Niño-Southern Oscillation (ENSO) is a key mode of climate variability with worldwide climate impacts. Recent studies have highlighted the impact of other tropical oceans on its variability. In particular, observations have demonstrated that summer Atlantic Niños (Niñas) favor the development of Pacific Niñas (Niños) the following winter, but it is unclear how well climate models capture this teleconnection and its role in defining the seasonal predictive skill of ENSO. Here we use an ensemble of seasonal forecast systems to demonstrate that a better representation of equatorial Atlantic variability in summer and its lagged teleconnection mechanism with the Pacific relates to enhanced predictive capacity of autumn/winter ENSO. An additional sensitivity study further shows that correcting SST variability in equatorial Atlantic improves different aspects of forecast skill in the Tropical Pacific, boosting ENSO skill. This study thus emphasizes that new efforts to improve the representation of equatorial Atlantic variability, a region with long standing systematic model biases, can foster predictive skill in the region, the Tropical Pacific and beyond, through the global impacts of ENSO.Item The stationarity of the ENSO teleconnection in european summer rainfall(Climate dynamics, 2022) Martija-Díez, Maialen; López-Parages, Jorge; Rodríguez De Fonseca, María Belén; Losada Doval, TeresaEl Niño-Southern Oscillation (ENSO) influence on European precipitation (Pcp) has been deeply analyzed. Most of the previous studies focus on the atmospheric response in wintertime during the peak of the ENSO episode, showing boreal summer a season with a marginal ENSO signal. Furthermore, the stationarity of the ENSO teleconnection with Europe has not been considered in many works, which could mask possible nonstationary impacts in other seasons like summer. In this research we find a strong influence of eastern Pacific-like ENSO on the leading variability mode of European summer Pcp, showing a dipole-like configuration and linking El Niño with drier(wetter) conditions in northern(southern) Europe. This relationship is not limited to the total cumulative Pcp, but also to the low and extreme Pcp. This impact on European rainfall is found from the 1960s to the 1990s, a 30 years-long period when the position of the extratropical northern jet stream, which acts as a waveguide, favors the teleconnection pathway to Europe. Strikingly, the ENSO events behind this teleconnection reach their peak in summer. However, we show that the resultant Pcp in Europe also depend on the ENSO characteristic of the previous seasons, which could be used for predictability purposes.Item Ocean dynamics shapes the structure and timing of Atlantic Equatorial Modes(Journal of geophysical research-oceans, 2019) Martín Rey, Marta; Polo Sánchez, Irene; Rodríguez De Fonseca, María Belén; Lazar, Alban; Losada Doval, TeresaA recent study has brought to light the co‐existence of two distinct Atlantic Equatorial Modes during negative phases of the Atlantic Multidecadal Variability: the Atlantic Niño and Horse‐Shoe (HS) mode. Nevertheless, the associated air‐sea interactions for HS mode have not been explored so far and the prevailing dynamic view of the Atlantic Niño has been questioned. Here, using a forced ocean model simulation, we find that for both modes, ocean dynamics is essential to explain the equatorial SST variations, while air‐sea fluxes control the off‐equatorial SST anomalies. Moreover, we demonstrate the key role played by ocean waves in shaping their distinct structure and timing. For the positive phase of both Atlantic Niño and HS, anomalous westerly winds trigger a set of equatorial downwelling Kelvin waves (KW) during spring‐summer. These dKWs deepen the thermocline, favouring the equatorial warming through vertical diffusion and horizontal advection. Remarkably, for the HS, an anomalous north‐equatorial wind stress curl excites an upwelling Rossby wave (RW), which propagates westward and is reflected at the western boundary becoming an equatorial upwelling KW. The uKW propagates to the east, activating the thermocline feedbacks responsible to cool the sea surface during summer months. This RW‐reflected mechanism acts as a negative feedback causing the early termination of the HS mode. Our results provide an improvement in the understanding of the TAV modes and emphasize the importance of ocean wave activity to modulate the equatorial SST variability. These findings could be very useful to improve the prediction of the Equatorial Modes.