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Coastal zones are under increasing development and experience air pollution episodes regularly. These episodes are often related to peaks in local emissions from industry or transportation, but can also be associated with regional transport from neighbour urban areas influenced by land-sea breeze recirculation. This study intends to analyze the relation between circulation weather patterns, air mass recirculation and pollution levels in three coastal airsheds of Portugal (Lisbon, Porto and Sines) based on the application of an objective quantitative measure of potential recirculation. Although ventilation events have a dominant presence throughout the studied 9-yrs period on all the three airsheds, recirculation and stagnation conditions occur frequently. The association between NO 2 , SO 2 and O 3 levels and recirculation potential is evident during summer months. Under high average recirculation potential and high variability, NO 2 and SO 2 levels are higher for the three airsheds, whilst for O 3 each airshed responds differently. This indicates a high heterogeneity among the three airsheds in (1) the type of emission – traffic or industry – prevailing for each contaminant, and (2) the response to the various circulation weather patterns and recirculation situations. Irrespectively of that, the proposed methodology, based on iterative K-means clustering, allows to identify which prevailing patterns are associated with high recirculation potential, having the advantage of being applicable to any geographical location. [ABSTRACT FROM AUTHOR]

Abstract: Mediterranean regions are some of the most affected by wildfires and remote-sensed information about fire activity, as provided by the SEVIRI instrument on-board Meteosat-8, is especially valuable for forest and civil protection activities. An analysis is performed of the spatial distribution of fire events during the period of July and August 2007–2009. Around half of fire pixels were detected in croplands, the remaining half being evenly distributed between forest and shrub, as opposed to the distribution of persistent fire events (more than 10h of duration) where 90% occurred in forest and shrub, evenly distributed between these two classes. With slightly more than half of the fire events and the most severe episodes, the year of 2007 is the most serious, allowing an assessment of the role of meteorological conditions on large fire events based on the analysis of low, mid and upper atmospheric fields of geopotential, temperature, relative humidity and wind. The analysis of two extreme events of fire activity that struck Greece and Italy on 24–25 July and 22–27 August, 2007 suggested a conceptual model for meteorological conditions favouring the occurrence of severe wildfire episodes in Italy and the Balkan Peninsula. On the one hand there is, at the surface, strong northerly advection of very hot and very dry air over the region, as steered by the presence of a ridge over central Europe together with a thermal depression over southwest Asia. On the other hand, the air advected is further heated by adiabatic compression associated to strong subsidence from around 700 up to 250hPa, associated to the presence of a ridge over the Eastern Mediterranean and to the anomalous displacement of the jet streak towards the northwest. The importance of both short- and long-term atmospheric conditions on meteorological fire risk is also put into evidence by analyzing the fields of three weather-based indices, namely the Build-Up Index, the Initial Spread Index and the Fire Weather Index that are part of the Canadian Forest Fire Weather Index System. Identified links of fire onset and fire persistence with land cover types and with atmospheric circulation patterns suggest using data on fire activity as derived from Meteosat-8/SEVIRI to generate statistically calibrated maps of fire risk in Mediterranean Europe. [Copyright &y& Elsevier]

Abstract: This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men''s excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r =0.79 for women and a poorer adjustment (r =0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement. [Copyright &y& Elsevier]

• A dependence among extreme values of yield and drought indicators is suggested. • VCI and SPEI are mainly associated to greater probabilities of joint low extremes. • Greater probabilities of joint high extremes of wheat are mainly associated to TCI. • Probability of crop-loss increases with drought severity in most of the provinces. • Barley exhibits greater agricultural drought risk in comparison to wheat. In a future climate, warmer and drier conditions are expected, and the associated negative impacts in agricultural productions are a major issue. Assessing the risk of drought hazard on agricultural systems is, therefore, of main importance in decision-making, with the aim of mitigating drought-related crop losses. In this study the agricultural drought risk is defined as the conditional probability of occurring crop-losses under drought conditions. We use the copula theory to estimate joint probability distributions describing the amount of dependence between drought conditions and crop yield anomalies of two major rainfed cereals in the Iberian Peninsula (wheat and barley), in the period 1986–2016. Further conditional probability distributions of the crop yield anomalies under different drought levels are obtained using the Standardized Precipitation Evapotranspiration Index (SPEI) and the satellite derived indices Vegetation Condition Index (VCI) and Temperature Condition Index (TCI). The results suggest that, in general, the joint behaviour of yield anomalies and drought conditions exhibits a dependence between the extreme values, whereas barley exhibits greater probabilities of joint extreme low values of yield and drought indicators. Moreover, while TCI is mainly used in copula models indicating greater probabilities of joint extreme high values of wheat and drought indicators (gumbel models), VCI and SPEI are mainly associated to copula models indicating greater probabilities of joint extreme low values (clayton models). The estimated conditional probabilities of occurrence of crop-loss are illustrated at the province level and suggest that agricultural drought risk increases with drought severity in most of the provinces. [ABSTRACT FROM AUTHOR]