Person: Mohino Harris, Elsa
Universidad Complutense de Madrid
Faculty / Institute
Física de la Tierra y Astrofísica
Física de la Tierra
Now showing 1 - 10 of 29
PublicationRepresentation and annual to decadal predictability of Euro-Atlantic weather regimes in the CMIP6 version of the EC-Earth Coupled Climate Model(American Geophysical Union, 2022-07-27) Delgado Torres, C.; Verfaillie, D.; Mohino Harris, Elsa; Donat, M.G.Weather regimes are large-scale atmospheric circulation states that frequently occur in the climate system with persistence and recurrence, and are associated with the occurrence of specific local weather conditions. This study evaluates the representation of the four Euro-Atlantic weather regimes in uninitialized historical forcing simulations and initialized decadal predictions performed with the EC-Earth3 coupled climate model. The four weather regimes are the positive and negative phases of the North Atlantic Oscillation (NAO+ and NAO−, respectively), Blocking, and Atlantic Ridge in winter; and the NAO−, Blocking, Atlantic Ridge, and Atlantic Low in summer. We also analyze the impact that the model initialization toward the observed state of the climate system has on the ability to predict the variability of the weather regimes' seasonal frequency of occurrence. We find that the EC-Earth3 model correctly reproduces the spatial patterns and climatological occurrence frequencies of the four weather regimes. By contrast, the skill in predicting the inter-annual to decadal variations of the weather regimes' seasonal frequencies is generally low, and the initialization does not significantly improve such skill. The observed teleconnections between the weather regimes and the North Atlantic sea surface temperatures are generally not reproduced by the model, which could be a reason for the low skill in predicting the temporal variations of the weather regime frequencies. PublicationSouthern hemisphere sensitivity to ENSO patterns and intensities: impacts over subtropical South America(MDPI AG, 2020-01-09) Martín Gómez, Verónica; Barreiro, Marcelo; Mohino Harris, ElsaEl Niño flavors influence Subtropical South American (SSA) rainfall through the generation of one or two quasi-stationary Rossby waves. However, it is not yet clear whether the induced wave trains depend on the El Niño pattern and/or its intensity. To investigate this, we performed different sensitivity experiments using an Atmospheric General Circulation Model (AGCM) which was forced considering separately the Canonical and the El Niño Modoki patterns with sea surface temperature (SST) maximum anomalies of 1 and 3 ◦C. Experiments with 3 ◦C show that the Canonical El Niño induces two Rossby wave trains, a large one emanating from the western subtropical Pacific and a shorter one initiated over the central-eastern subtropical South Pacific. Only the shorter wave plays a role in generating negative outgoing longwave radiation (OLR) anomalies over SSA. On the other hand, 3 ◦C El Niño Modoki experiments show the generation of a large Rossby wave train that emanates from the subtropical western south Pacific and reaches South America (SA), promoting the development of negative OLR anomalies over SSA. Experiments with 1 ◦C show no impacts on OLR anomalies over SSA associated with El Niño Modoki. However, for the Canonical El Niño case there is a statistically significant reduction of the OLR anomalies over SSA related to the intensification of the upper level jet stream over the region. Finally, our model results suggest that SSA is more sensitive to the Canonical El Niño, although this result may be model dependent. PublicationImpact of dynamical regionalization on precipitation biases and teleconnections over West Africa(Springer, 2018-06) Gómara Cardalliaguet, Íñigo; Mohino Harris, Elsa; Losada Doval, Teresa; Domínguez, Marta; Suárez Moreno, Roberto; Rodríguez 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. PublicationDecadal variability of rainfall in Senegal: beyond the total seasonal amount(American Meteorological Society, 2022-08-15) Badii, Aïssatou; Mohino Harris, Elsa; Diakhaté, Moussa; Mignot, Juliette; Gayé, Amadou ThiernoThe rainfall characteristics are crucial in monsoon regions, in particular for agriculture. Crop yields indeed depend on the rainfall seasonal amounts, but also on other rainfall characteristics such as the onset of the rainy season or the distribution of rainy days. In the Sahel region, while the average amount of seasonal rainfall has been shown to be marked by strong decadal variability, the modulation of rainfall characteristics has received less attention in the literature so far. In this study, we show that the frequency of the light, heavy and extreme rainfall events and the mean intensity of rainfall events in Senegal exhibit a marked decadal variability over the 1918-2000 period, strongly similar to that of the mean seasonal rainfall. The decadal modulations of these events show a strong and positive link with the Atlantic Multidecadal Variability (AMV). Indeed, positive sea surface temperature anomalies over the North Atlantic and Mediterranean related to a warm AMV phase are associated with negative sea level pressure anomalies over the northern Atlantic and a northward shift of the intertropical convergence zone. We also find that the onset and cessation dates as well as the length of the rainy season show relatively less decadal variability, which is more related to the Interdecadal Pacific Oscillation (IPO), a positive phase of the latter leading to a late onset, an early cessation and an overall shorter rainy season in Senegal. PublicationAtlantic control of the late nineteenth-century Sahel humid period(American Meteorological Society., 2018-10-15) Villamayor Moreno, Julián; Mohino Harris, Elsa; Juliette, Mignot; Serge, JanicotPrecipitation regime shifts in the Sahel region have dramatic humanitarian and economic consequences such as the severe droughts during the 1970s and 1980s. Though Sahel precipitation changes during the late twentieth century have been extensively studied, little is known about the decadal variability prior to the twentieth century. Some evidence suggests that during the second half of the nineteenth century, the Sahel was as rainy as or even more rainy than during the 1950s and 1960s. Here, we reproduce such an anomalous Sahel humid period in the late nineteenth century by means of climate simulations. We show that this increase of rainfall was associated with an anomalous supply of humidity and higher-than-normal deep convection in the mid- and high troposphere. We present evidence suggesting that sea surface temperatures (SSTs) in the Atlantic basin played the dominant role in driving decadal Sahel rainfall variability during this early period. PublicationThe tropical Atlantic observing system(Frontiers Media, 2019-05-10) Rodríguez Fonseca, María Belén; Polo Sánchez, Irene; Losada Doval, Teresa; Mohino Harris, Elsa; López Parages, JorgeThe tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world’s largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set of research priorities and operational challenges. This paper discusses the tropical Atlantic observing system, including emerging scientific questions that demand sustained ocean observations, the potential for further integration of the observing system, and the requirements for sustaining and enhancing the tropical Atlantic observing system. PublicationCreación de recursos prácticos y digitales de meteorología y clima a través de Metolab(2023-07-27) Losada Doval, Teresa; Ayarzaüena Porras, Blanca; Benito Barca, Samuel; Calvo Fernández, Natalia; Calvo Miguélez, Elena; Cámara Illescas, Álvaro de la; Durán Montejano, Luis; García Burgos, Marina; García Herrera, Ricardo Francisco; Garrido Pérez, José Manuel; Gómara Cardalliaguet, Íñigo; López Reyes, Mauricio; Martín del Rey, Marta; Martín Gómez, Verónica; Martínez Andradas, Verónica; Mohino Harris, Elsa; Ortiz Corral, Pablo; Polo Sánchez, Irene; Rodríguez de Fonseca, María Belén; Román Cascón, Carlos; Sastre Marugán, Mariano; Yagüe Anguís, Carlos; Zurita Gotor, Pablo; Calvo Miguélez, Elena PublicationInfluence of decadal sea surface temperature variability on northern Brazil rainfall in CMIP5 simulations(Springer, 2018-07) Villamayor Moreno, Julián; Ambrizzi, Tércio; Mohino Harris, ElsaThe Amazonia and Northeast regions of northern Brazil are characterized by very different rainfall regimes but have certain similarities in terms of their variability. The precipitation variability in both regions is strongly linked to the tropical Atlantic sea surface temperature (SST) gradient and the tropical Pacific SST anomalies, which at decadal timescales are modulated by the Atlantic Multidecadal Variability (AMV) and the Interdecadal Pacific Oscillation (IPO) modes of SST, respectively. On the other hand, it has been found that state-of-the-art models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) are able to reproduce some of the characteristics of the low-frequency SST variability modes. In this work we analyze how CMIP5 models simulate the observed response of precipitation in the Amazonia and Northeast regions to the AMV and the IPO and the atmospheric mechanisms involved. Results show that, in both CMIP5 simulations and observations, Amazonia and Northeast rainfall response to the AMV is the opposite, due to the modulation of the intertropical convergence zone (ITCZ) position. Conversely, the IPO affects equally both regions as a consequence of anomalous subsidence over the entire northern Brazil triggered by warm SST anomalies in the tropical Pacific. Such results suggest that an improvement of the predictability of decadal SST modes will directly revert into a better prediction of changes in the Amazonia and Northeast rainfall at longer timescales. PublicationOn the detection of externally forced decadal modulations of the Sahel rainfall over the whole twentieth century in the CMIP6 ensemble(American Meteorological Society, 2022-11-01) Ndiaye, Cassien D.; Mohino Harris, Elsa; Mignot, Juliette; Sall, Saidou M.The Sahel semiarid region was marked during the twentieth century by significant modulations of its rainfall regime at the decadal time scale. Part of these modulations have been associated with the internal variability of the climate system, linked to changes in oceanic sea surface temperature. More recently, several studies have highlighted the influence of external forcings during the dry period in the 1980s and the recovery around the 2000s. In this work we evaluate the internally and externally driven decadal modulations of Sahel rainfall during the entire twentieth century using a set of 12 models from phase 6 of the Coupled Model Intercomparison Project (CMIP6). We begin by proposing a physically based definition of Sahel rainfall that takes into account the southward bias in the location of the Sahelian ITCZ simulated by all the models. Our results show that the amplitude of the decadal variability, which is underestimated by most models, is mainly produced by the internally driven component. Conversely, the external forcing tends to enhance the synchrony of the simulated and observed decadal modulations in most models, providing statistically significant correlations of the historical ensemble mean with observations in 1/3 of the models, namely IPSL-CM6A-LR, INM-CM5-0, MRI-ESM2-0, and GISS-E2-1-G. Further analysis of the detection and attribution runs of the IPSL-CM6A-LR shows that anthropogenic aerosol dominate the decadal modulations of Sahel rainfall simulated by this model, suggesting that at least a part of the impact is ocean-mediated and operated through shifts in the ITCZ and the Saharan heat low. PublicationDesarrollo del catálogo OSCAR y su difusión en diferentes ámbitos docentes(2015-07-10) Dinis Vizcaíno, Luis Ignacio; Barragán García, Vicenta María; Contreras González, José Luis; Barrio Uña, Juan Abel; Godino Gómez, María Paz; Izquierdo Gil, María Amparo; Mohino Harris, Elsa; Rodríguez López, Oscar; Rodríguez Pérez, Oscar; Zarco Moreno, ManuelEn convocatorias anteriores de los PIMCD se ha desarrollado un Catálogo de experiencias de cátedra para la docencia de Física General que cuenta actualmente con más de 40 experiencias en funcionamiento disponibles en el Laboratorio de Física General de la Facultad de Ciencias Físicas. Muchas de las experiencias son trasladables para su utilización en el aula. Cada una de las experiencias se acompaña de una ficha explicativa (con una foto, descripción,fundamento teórico, materiales y montaje…). Además, prácticamente todas (34) las experiencias disponen de material audiovisual (uno o dos vídeos que muestran la experiencia en funcionamiento y una explicación) en su mayor parte subtitulado en inglés. También muchas de ellas están acompañadas de un cuestionario destinado a los alumnos para el mejor aprovechamiento de la explicación de la experiencia o el vídeo en el aula o en procesos de autoaprendizaje online. El catálogo se completa con una página web institucional (http://www.ucm.es/theoscarlab) y un canal de YouTube (https://www.youtube.com/user/TheOscarlab) donde se muestran los vídeos y en la que se interactúa con los usuarios a través de comentarios y correos electrónicos. Las visitas al canal superan ya el número de 200.000 desde su creación en abril de 2012. Además, tradicionalmente las experiencias del catálogo se han utilizado en numerosas ediciones de la Semana de la Ciencia en la actividad “Jugando con la Física” y en visitas guiadas de alumnos de colegios, institutos y otros centros educativos a la Facultad de Ciencias Físicas. El catálogo resultante de este proyecto constituye la v versión más amplia y actualizada y refleja más fielmente las experiencias disponibles en el Laboratorio de Física General.