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African dust intrusions in the marine mixing layer of the Eastern North Atlantic subtropical region (23.5◦N to 35◦N) are favoured in winter when the eastern edge of the Azores High covers Southwestern Europe and North Africa. In situ ground pressure observations and reanalysis from National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and European Centre for Medium-Range Weather Forecasts (ECMWF) indicate that the Azores High has strengthened and shifted eastward in winter over the last three decades. This is evidenced by the increase over time of the Madrid–Tenerife Index which is defined as the geopotential height anomaly difference at 1000 mb between Tenerife (28.5◦N; 16.3◦W) and Madrid (40.5◦N; 3.5◦W) in winter and of the African Index which is defined as the residence time over Africa of air mass trajectories entering the subtropical Eastern North Atlantic Ocean. Barcelona Supercomputing Center/Dust Regional Atmospheric Model (BSC-DREAM) dust regional model simulations from 1958 to 2006 were performed, assuming that the soil characteristics of dust sources remained unchanged over time. Simulated winter dust concentration levels are well correlated (0.67) with the available background observations for the 1998–2004 period. The model results show a two-fold increase in winter dust concentrations over the 1980–2006 period with respect to the 1958–1979 period, corresponding to the strengthening and eastward shift of the Azores High.

Objetivo. Evaluar si la exposición a episodios de polvo sahariano predice los ingresos hospitalarios de los pacientes con insuficiencia cardiaca aguda (ICA) atendidos en un servicio de urgencias hospitalario (SUH).Método. Estudio unicéntrico, de cohorte retrospectiva, de pacientes con ICA atendidos en un SUH. La población de estudio se dividió en 2 grupos: pacientes ingresados por ICA y pacientes con ICA dados de alta directa a domicilio desde el SUH. Se analizaron las concentraciones medias de material partículado (PMx) (respirables, diámetro aerodiná-mico, da < 10 μm), PM2,5 (finas, da < 2,5 μm) y PM2,5-10 (gruesas, da 2,5-10 μm) desde el día de la llegada al SUH hasta 5 días previos. Se definió exposición intensa al polvo sahariano cuando las concentraciones medias diarias de PM10 estaban entre 50 y 200 μg/m3. La relación para estimar el riesgo de ingresar por ICA en función de la exposición de PMx durante los 5 días previos a su llegada a urgencias se analizó mediante análisis multivariable.Resultados. Se incluyeron 1.097 pacientes con ICA, ingresaron 318 pacientes (29%), 779 (71%) se dieron de alta. Los pacientes ingresados por ICA tenían mayor edad, elevada comorbilidad y mayor proporción de pacientes expuestos a episodios intensos de polvo sahariano (p < 0,0001). En el análisis multivariable la exposición a episodios de polvo saha-riano intensos se relacionó con el ingreso hospitalario en los pacientes con ICA (OR = 2,36; IC 95% 1,21-4,58; p = 0,01).Conclusiones. En ausencia de estudios prospectivos, los resultados obtenidos de la serie analizada sugieren que la presencia de concentraciones elevadas de polvo sahariano (PM10: 50-200 μg/m3) puede constituir un factor precipi-tante de ingreso por ICA. Objectives: To explore whether episodes of exposure to atmospheric Saharan dust is a risk factor for hospitalization in patients with acute heart failure (AHF) attended in a hospital emergency department (ED). Methods: Single-center retrospective study of patients with AHF. The cohort was analyzed in 2 groups: ED patients hospitalized with AHF and patients discharged home from the ED. Air pollution on the 5 days leading to ED admission for AHF was recorded as the average concentration of breathable particulate matter with an aerodynamic diameter of no more than 10 µm (PM10) in the following ranges: fine PM (diameter less than 2.5 µm) or coarse PM (diameters between 2.5 and 10 µm). High Saharan dust pollution exposure was defined by mean daily PM10 concentrations between 50 and 200 µg/m3. Multivariable analysis was used to estimate risk for AHF in relation to PM10 exposure in the 5 days before the ED visit. Results: A total of 1097 patients with AHF were treated in the ED; 318 of them (29%) were hospitalized and 779 (71%) were discharged home. Hospitalized patients were older, had more concomitant illnesses, and more episodes of exposure to Saharan dust (P < .0001). Multivariable analysis confirmed the association between Saharan dust exposure and hospital admission in these patients (odds ratio, 2.36; 95% CI, 1.21-4.58; P = .01). Conclusion: In the absence of prospective studies, the results of this series suggest that exposure to high levels of Saharan dust (PM10 concentrations between 50 and 200 µg/m3) may be a precipitating factor for hospitalization in AHF episodes. Keywords: Acute heart failure; Precipitating factors; Saharan dust; Polvo sahariano; Servicio de Urgencias; Emergency health services; Factor precipitante; Insuficiencia cardiaca aguda. Sin financiación 3.173 JCR (2019) Q1, 4/31 Emergency Medicine 0.373 SJR (2019) Q2, 36/87 Emergency Medicine No data IDR 2019 UEC

In this study, we revise the index that quantifies the North African Dipole Intensity (NAFDI), and explain its relationship with the Saharan Heat Low (SHL) and mid-latitude Rossby waves. We find outstanding similarities of meteorological patterns associated with the positive NAFDI and the SHL West-phase on the one hand, and with the negative NAFDI and the SHL East-Phase, on the other hand. We introduce the daily NAFDI index and the daily SHL West-East Displacement Index (SHLWEDI). The Pearson correlation coefficient between the daily SHLWEDI 1-day lagged and the daily NAFDI for the period 1980–2013 20 June–17 September is fairly high (r = 0.77). The correlation reduces to 0.69 if the SHLWEDI is not lagged. We observe that the SHL West-phase is significantly more frequent than the SHL East-phase, and that the SHL is more intense during its East-phase. Part of this study was performed in the frame of AEROATLAN (grant 2015-66229), funded by the Ministry of Economy and Competitiveness of Spain.

More than 2 years of columnar atmospheric aerosol measurements (2006–2009) at the Tamanrasset site (22.79° N, 5.53° E, 1377 m a.s.l.), in the heart of the Sahara, are analysed. Aerosol Robotic Network (AERONET) level 2.0 data were used. The KCICLO (K is the name of a constant and ciclo means cycle in Spanish) method was applied to a part of the level 1.5 data series to improve the quality of the results. The annual variability of aerosol optical depth (AOD) and Ångström exponent (AE) has been found to be strongly linked to the convective boundary layer (CBL) thermodynamic features. The dry-cool season (autumn and winter) is characterized by a shallow CBL and very low mean turbidity (AOD ~ 0.09 at 440 nm, AE ~ 0.62). The wet-hot season (spring and summer) is dominated by high turbidity of coarse dust particles (AE ~ 0.28, AOD ~ 0.39 at 440 nm) and a deep CBL. The aerosol-type characterization shows desert mineral dust as the prevailing aerosol. Both pure Saharan dust and very clear sky conditions are observed depending on the season. However, several case studies indicate an anthropogenic fine mode contribution from the industrial areas in Libya and Algeria. The concentration weighted trajectory (CWT) source apportionment method was used to identify potential sources of air masses arriving at Tamanrasset at several heights for each season. Microphysical and optical properties and precipitable water vapour were also investigated. The AERONET sun photometer at Tamanrasset has been calibrated within AERONET-EUROPE TNA supported by the PHOTONS and RIMA networks and partially financed by the European Community – Research Infrastructure Action under the Seventh Framework Programme (FP7/2007-2013) “Capacities” specific programme for Integrating Activities, ACTRIS grant agreement no. 262254. Financial support from the Spanish MINECO (projects CGL2011-23413, CGL2012-33576 and CGL2012-37505) is also gratefully acknowledged. J. M. Baldasano and S. Basart acknowledge the Supercomputación y eCiencia project (CSD2007-0050) from the Consolider-Ingenio 2010 and Severo Ochoa (SEV-2011-00067) programs of the Spanish Government.

We have studied the relationship between the long-term interannual variability in large-scale meteorology in western North Africa – the largest and most active dust source worldwide – and Saharan dust export in summer, when enhanced dust mobilization in the hyper-arid Sahara results in maximum dust impacts throughout the North Atlantic. We address this issue by analyzing 28 years (1987–2014) of summer averaged dust concentrations at the high-altitude Izaña observatory (~ 2400 m a.s.l.) on Tenerife, and satellite and meteorological reanalysis data. The summer meteorological scenario in North Africa (aloft 850 hPa) is characterized by a high over the the subtropical Sahara and a low over the tropics linked to the monsoon. We measured the variability of this high–low dipole-like pattern in terms of the North African dipole intensity (NAFDI): the difference of geopotential height anomalies averaged over the subtropics (30–32° N, Morocco) and the tropics (10–13° N, Bamako region) close to the Atlantic coast (at 5–8° W). We focused on the 700 hPa standard level due to dust export off the coast of North Africa tending to occur between 1 and 5 km a.s.l. Variability in the NAFDI is associated with displacements of the North African anticyclone over the Sahara and this has implications for wind and dust export. The Izaña GAW program is funded by AEMET and by the Minister of Economy and Competitiveness of Spain (POLLINDUST, CGL2011-26259). J. M. Prospero’s research is supported by NSF grant AGS-0962256.

The occurrence of African dust outbreaks over different areas of the western Mediterranean Basin were identified on an 11-year period (2001–2011). The main atmospheric circulation patterns causing the transport of African air masses were characterized by means of an objective classification methodology of atmospheric variable fields. Next, the potential source areas of mineral dust, associated to each circulation pattern were identified by trajectory statistical methods. Finally, an impact index was calculated to estimate the incidence of the African dust outbreaks produced during each circulation pattern, in the areas of study. This work was funded by the Spanish Ministry of the Environment and Rural and Marine Affairs under the project “Estudio y evaluacion de la contaminacion atmosferica por material particulado y metales en España” (UCA 2009020083) and by research projects GRACCIE-CSD2007-00067, MICROSOL (CGL2011-27020) and VAMOS (CGL2010-19464/CLI).

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.

An analysis of the 22-yr ozone (O3) series (1988– 2009) at the subtropical high mountain Izaña station (IZO; 2373m a.s.l.), representative of free troposphere (FT) conditions, is presented. Diurnal and seasonal O3 variations as well as the O3 trend (0.19±0.05%yr−1 or 0.09 ppbvyr−1), are assessed. A climatology of O3 transport pathways using backward trajectories shows that higher O3 values are associated with air masses travelling above 4 km altitude from North America and North Atlantic Ocean, while low O3 is transported from the Saharan continental boundary layer (CBL).

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.

The authors wish to thank to different projects and entities for financing this study: COST ES0603 EUPOL; Laboratorios LETI S.A.; Proyecto EOLO-PAT; European Commission for «ENV4-CT98-0755»; Spanish Ministry of Science and Technology I+D+I for «AMB97-0457-CO7-021», «REN2001-10659-CO3-01», «BOS2002-03474», «CGL2004-21166-E», «CGL2005-07543/CLI», «CGL2009-11205» and CONSOLIDER CSD2007_00067 GRACCIE; Andalusian Government for «RNM-5058»; and Catalan Government AGAUR for «2002SGR00059», «2005SGR00519» and «2009SGR1102».

Comunicación presentada en: V Reunión Española de Ciencia y Tecnología de Aerosoles – RECTA 2011 celebrada del 27 al 29 de junio de 2011 en CIEMAT, Madrid.

An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate

Comunicación presentada en: V Reunión Española de Ciencia y Tecnología de Aerosoles – RECTA 2011 celebrada del 27 al 29 de junio de 2011 en CIEMAT, Madrid. This study presents an inter-comparison between a Vaisala CL51 ceilometer and a Micro Pulse Lidar (MPL) of both the Boundary Layer (BL) and the Saharan Air Layer (SAL) top heights during Saharan dust events from January to April 2011. This inter-comparison was performed at the Santa Cruz de Tenerife Observatory in Tenerife, Canary Islands, within the Marine Boundary Layer. From January to April the Saharan dust intrusions usually occur at lower altitudes within the BL. One of the main goals of this study is to determine whether the CL51 ceilometer is capable to detect mineral dust within the SAL. To our knowledge, this is the first time this kind of study is attempted on a site close to Saharan dust sources.

Comunicación presentada en: V Reunión Española de Ciencia y Tecnología de Aerosoles – RECTA 2011 celebrada del 27 al 29 de junio de 2011 en CIEMAT, Madrid.

El agua precipitable representa la cantidad de agua que se obtendría si todo el vapor de agua contenido en una cierta columna vertical de aire se condensase y precipitase. El objeto de esta nota técnica es el de desarrollar una climatología del vapor de agua basada en las medidas de agua precipitable obtenidas a través de radiosondas de presión, temperatura y humedad (PTU) lanzadas en Tenerife.

Comunicación presentada en: Symposium on Atmospheric Chemistry and Physics at Mountain Sites celebrado del 8 al 10 de junio de 2010 en Interlaken, Suiza.

Póster presentado en: 37th Annual European Meeting on Atmospheric Studies by Optical Methods, celebrado en 2010 en Valladolid. Financial supports from the Spanish MICIIN (ref.CGL2008-05939-CO3-00/CLIandCGL2009-09740) and from the GR-220 Project of the Junta de Castilla y León are gratefully acknowledged.

This manuscript proposes and validates a methodology for the quantification of the daily African PM load during dust outbreaks in southern Europe. The daily net dust load in PM10 attributable to an African episode can be obtained by subtracting the daily regional background (RB) level from the PM10 concentration value at a RB station. The daily RB level can be obtained by applying a monthly moving 30th percentile to the PM10 time series at a RB station after a prior extraction of the data coincident with African dust transport. For days with influence of African dust, the dust load is given by the difference between the daily PM10 values minus the daily PM10 RB levels. This method allows us to quantify the net African dust load without chemical speciation. The comparison between the estimated net load during African dust outbreaks (ADO) and the crustal load determined by chemical speciation of PM10 filters at three RB stations in Spain had resulted in a very good correlation (R2=0.60-0.83), being the equivalence (correlation lines’ slopes ~ 1) highly significant in the three cases. This study was supported by the S.G.D. Environmental Quality and Industrial Environment from the Spanish Ministry of the Environment, but also by research projects from the Ministry of Science and Innovation (CGL2005-03428- C04-03/CLI, CGL2007-62505/CLI, GRACCIE- CSD2007-00067), the European Union (6th framework CIRCE IP, 036961, EUSAAR RII3-CT-2006-026140) and the Ministry of the Environment (CALIOPE, 441/2006/3-12.1).

During the last 7-year period (2000-2006) atmosphere circulation changes show strong influences on the dust storm deposition dynamics and, as a result, on the primary production dynamics of the northwest African Upwelling System. From 2000 to 2006, the annual mean sea level pressure became higher ranging from 1014 to 1015 mb. Mean annual zonal wind intensity became higher (from 1.1 to 1.8 m s-1), while the mean annual meridional was reduced from 6.2 to 5.3 m s-1 at the north of the Canary Islands. Mean annual satellite-derived AVHRR/NOAA SST recorded in the northwest African Upwelling became warmer in both locations, from 18.3ºC to 18.8ºC in Cape Ghir and from 19.5ºC to 20.3ºC north Canary Islands waters. CHL records from the SeaWiFS/OV-2 showed a different pattern trend. Mean annual CHL levels increased at Cape Ghir from 0.65 mg m-3 to 0.9 mg m-3 and significantly reduced from 0.59 mg m-3 to 0.31 mg m-3 at the north of the Canary Islands. Changes observed in the role of CHL during the last 7-years period could be associated to intensive dust deposition and exceptional weather warming observed in this area since 2000. However, this study focused on a 7-year period and conclusions on possible links between dust deposition and marine biochemistry activity cannot be generalized.

Memoria presentada para optar al Grado de Doctor en Ciencias Físicas por la Universidad de La Laguna. Departamento de Física Básica En este trabajo multidisciplinar se caracterizan los episodios de intrusión de masas de aire con elevada carga de polvo africano en Canarias desde el punto de vista de su impacto en niveles de partículas, origen del material particulado y escenarios meteorológicos a escala sinóptica que favorecen estos episodios. Asimismo, se aborda el estudio de la relación de estos episodio con índices de teleconexión, evaluación de tendencias temporales de los episodios de polvo y utilización de los isótopos 137Cs, 40K y 7Be como trazadores de estos episodios. Además, se presentan los resultados de la validación para Canarias del sistema de predicción y alerta de episodios de polvo africano que desde 2003 se encuentra operativo para toda España.