Application of a source-receptor model to determine source areas of pollen in Catalonia (NE Spain)

In this study we characterize the long-range transport of allergenic pollen to the North East of Spain. To this end, cluster analysis of back-trajectories and a source-receptor model was applied to a dataset of 10 years of airborne monitoring data corresponding to the period 2000-2009. The aim of the study is to examine and interpret the main transport routes and source areas affecting levels in Catalonia for a total of 20 pollen types. The cluster analysis of trajectories revealed that trajectories entering to the region by East France represent well the long distant transport of some taxa which are scarce in the Catalan territory or present only in limited areas (Ambrosia, Betula, Corylus and Fagus) together with other common in Catalonia (Fraxinus, Quercus deciduous type and Pistacia) showing agreement with the source areas obtained from the source-receptor methodology: Whereas, for taxa with local/regional sources (Artemisia, Castanea, total Poaceae, Plantago, total Polygonaceae, Olea, total Quercus and Quercus evergreen type) with high concentration levels associated to situations of recirculation over the Iberian Peninsula, the source-receptor model did not show reliable source regions.Peer Reviewe

Patrons de transport atmosfèric i tendències en la química de la precipitació del Montseny

L’objectiu d’aquest estudi és interpretar els canvis de la química de la pluja dels últims vint-i-cinc anys al Montseny. Els mètodes d’anàlisi estadístic de trajectòries (TSMs) indiquen que en el período 1984-1993 els contaminants antropogènics (SO42–,H+ i NO3–) que es dipositaven al Montseny procedien principalment de l’Europa Central i Oriental. La disminució significativa de les concentracions de SO4 2– i H+ reflecteix la reducció de les emissions de sofre al centre d’Europa. En el período 1998-2009, l’origen de SO42–, H+ i NO3– es pot atribuir al trànsit marítim al mar del Nord i als països de l’est d’Europa i el nord d’Àfrica.Postprint (published version

WeMO effects on the amount and the chemistry of winter precipitation in the north-eastern Iberian Peninsula

The cluster classification of provenances at a site in the NE Iberian Peninsula indicated that in the period of extended winter (December to March, DJFM) fast Atlantic air flows correspond to positive WeMO index (WeMOi), while negative WeMOi are associated to Mediterranean circulations. The amount of winter precipitation was inversely correlated with winter WeMOi. Wet deposition fluxes of marine-derived (Na+, Mg2+ and Cl) and anthropogenic-derived (NO3 and K+) ions were significantly (and negatively) related to winter WeMOi. The negative phase of WeMO causes the entry of air masses from the Mediterranean into the Iberian Peninsula, that are enriched with marine ions. For NO3 this result suggests the advection over the Mediterranean of polluted air masses from southern Europe and the scavenging and deposition of this pollution by rain during WeMO negative phases. This will carry long-range pollutants to the NE Iberian Peninsula, but local pollutants may also contribute, as precipitation events from the Mediterranean (associated to negative WeMOi) may incorporate local anthropogenic emissions that build up during the winter anticyclonic episodes typical of the region.Postprint (published version

Influence of the WeMO and NAO decadal trends on the airborne pollen levels recorded in Catalonia (NW Mediterranean basin)

Airborne pollen records constitute a powerful tool for different purposes. First, in studies of dispersion and source identification of pollen grains, which, incorporated into the atmosphere by anemophilous plants, produce allergic symptoms in a part of the population sensitive to it. On the other hand, aerobiological databases provide useful information for the understanding of the trends induced by the climate change. The decadal series allow the extraction of patterns with intra-annual variability (seasonality of the events and their relationship with the atmospheric transport patterns) and inter-annual variability (inter-annual trends and its possible relationship with climatic variability indexes). The longer the aerobiological monitoring series the better the understanding of the effects of climate change on pollination trends. The aim of this study is to explore the influence of climate change on the airborne pollen series recorded in Catalonia during the period 1994-2012 by the analysis of its correlation with both, the North Atlantic Oscillation (NAO) and the new regional teleconnection Western Mediterranean Oscillation (WeMO) defined within the synoptic framework of the western Mediterranean basin

Airborne pollen parameters and their relationship with meteorological variables in NE Iberian Peninsula

The present study explores the role of the meteorological variability in the pollen production and the timing of the airborne pollen season by analysis of the correlation between precipitation, insolation and temperature and the main standardised airborne pollen parameters of 22 taxa collected at 6 localities in Catalonia (NE Spain). The pollen parameters included in the study were: Annual Pollen Integral and the Start, End and Length of the Main Pollen Season. Considering that the Main Pollen Season of most of the taxa in Catalonia lasts from spring to summer or autumn, correlations between the pollen parameters and winter (from December to March) values of meteorological variables were calculated. Correlations between Monthly Pollen Integral and monthly values of the meteorological variables were also calculated. The results obtained report the synchronism registered in the variations of pollen concentration with precipitation (negative), insolation (positive) and temperature (positive). Temperature was the meteorological variable that showed a greater influence in the pollen production and the timing of the pollen season, being insolation the least one. The Start of the Main Pollen Season was the pollen parameter more correlated with the meteorological variables, especially with winter temperatures.Peer ReviewedPostprint (author's final draft

Are the Pyrenees a barrier for the transport of birch (Betula) pollen from Central Europe to the Iberian Peninsula?

This work provides a first assessment of the possible barrier effect of the Pyrenees on the atmospheric transport of airborne pollen from Europe to the North of the Iberian Peninsula. Aerobiological data recorded in three Spanish stations located at the eastern, central and western base of the Pyrenees in the period 2004–2014 have been used to identify the possible long range transport episodes of Betula pollen. The atmospheric transport routes and the origin regions have been established by means of trajectory analysis and a source receptor model. Betula pollen outbreaks were associated with the meteorological scenario characterized by the presence of a high-pressure system overm over Morocco and Southern Iberian Peninsula. France and Central Europe have been identified as the probable source areas of Betula pollen that arrives to Northern Spain. However, the specific source areas are mainly determined by the particular prevailing atmospheric circulation of each location. Finally, the Weather Research and Forecasting model highlighted the effect of the orography on the atmospheric transport patterns, showing paths through the western and easternmost lowlands for Vitoria-Gasteiz and Bellaterra respectively, and the direct impact of air flows over Vielha through the Garona valley.Peer ReviewedPreprin

Aplicació de models font-receptor per a determinar àrees font de components biològics (pol·len i papallones)

Els models font-receptor permeten establir relacions entre un punt receptor (punt de mostreig) i les àrees font probables (regions emissores) mitjançant l'associació de valors de concentració en el punt receptor amb les corresponents retrotrajectòries atmosfèriques, i, juntament amb altres tècniques, permeten interpretar fenòmens de transport a escala sinòptica. No obstant això, fins a l'actualitat, pocs treballs han aplicat aquests tipus de models per descriure les àrees font d'organismes biològics. A Catalunya es disposa de registres molt complets de pol·len (dades de la Xarxa Aerobiològica de Catalunya) i de papallones (dades del Catalan Butterfly Monitoring Scheme), un material biològic també susceptible de ser transportat a llargues distàncies i del que pot interessar conèixer les seves àrees d'origen. En aquest treball presentem els resultats de l'ús del model de Seibert et al. aplicat a l'estudi de les regions font de: (1) determinats pol·lens de caràcter al·lergogen, observats a Catalunya i Canàries, i (2) la papallona migratòria Vanessa cardui, observada a Catalunya. Amb els resultats obtinguts podem corroborar la idoneítat d'aquests models per a explicar la procedència de diferents espècies, tant químiques com biològiques, ampliant així les possibilitats d'aplicació del model original al camp molt més extens de l'aerobiologia

Migration of the painted lady butterfly, Vanessa cardui, to north-eastern Spain is aided by African wind currents

1. Thousands of records of migratory butterfly species such as Vanessa cardui flying just above ground-level on fixed compass bearings have led to the common belief that these insects migrate within the so-called 'flight-boundary layer', where movements are relatively independent of the wind.- 2. Given the selective advantages of windborne migration and the existence of a number of observations of flights of V. cardui from the upper levels of the atmosphere, we tested the hypothesis that migration from North Africa to southern Europe in this species is influenced by synoptic-scale wind currents.- 3. Even with modern technology, it is extremely difficult to observe high-altitude flights directly, so we rely on an indirect approach that examines whether or not arrival peaks in north-eastern Spain are associated with winds blowing from Africa.- 4. Arrivals of V. cardui were determined for the spring period (1 March-27 June, 1997-2006) at 79 sites in the Catalan Butterfly Monitoring Scheme. Wind patterns were described on the basis of synoptic-scale maps, transport models and back-trajectories calculated for each day of the spring period. 5.- We found a strong association between migration and winds from North Africa, both for the whole data set (1997-2006; chi(2) = 4.7, P = 0.03) and for a restricted data set that excludes years in which the species was very scarce (chi(2) = 7.26, P = 0.007).- 6. Episodes of massive northward migration within the species' flight-boundary layer also coincided with spells of winds from North Africa, suggesting a connection between low-altitude (observational) and high-altitude flights (inferred from wind patterns).- 7. Finally, on the assumption that migration in V. cardui is windborne, a source-receptor transport model applied to spring abundance data in north-eastern Spain enables us to identify the most probable population source areas in North Africa

Relationship between climate variability indices and airborne pollination in Catalonia (NE Iberian Peninsula)

Here we explore the effect of climatic variability on the airborne pollen series recorded in Catalonia (NE Iberian Peninsula) considered of high interest due to abundance, landscape importance and/or allergenic significance. In this sense, the relationship between the annual and winter (December to March) phases of the North Atlantic Oscillation (NAO), the Western Mediterranean Oscillation (WeMO) and the Arctic Oscillation (AO) and the Annual Pollen Index (API), the start, the end and the length of the pollination seasons of 22 taxa collected at 6 aerobiological stations in Catalonia during the 18 years-period 1994-2011 have been computed. In addition, daily back-trajectories cluster analysis has been carried out in order to determine the influence of climatic indices on the main atmospheric transport routes frequencies and the long range pollen transport. Our aim is to determine the respective vulnerability of taxa to climate variability, taking also into account the pollen provenance area. Climatic indices showed significant negative correlations with the parameters API (except for Corylus) and pollination start (except for Ambrosia, Castanea, Fagus and Betula, the latter being Eurosiberian taxa often long range transported) of most taxa, while significant positive correlations with the end of the pollination period of most taxa. The most vulnerable taxa (more significant correlations) with regard to API were Corylus, Olea, Platanus and Quercus deciduous type.Postprint (published version