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The effect of aerosols on regional climate simulations presents large uncertainties due to their complex and non-linear interactions with a wide variety of factors, including aerosol–radiation (ARI) and aerosol–cloud (ACI) interactions. These interactions are strongly conditioned by the meteorological situation and type of aerosol, but, despite their increase, only a limited number of studies have covered this topic from a regional and climatic perspective. This contribution thus aims to quantify the impacts on precipitation of the inclusion of ARI and ACI processes in regional climate simulations driven by ERA20C reanalysis. A series of regional climatic simulations (for the period 1991–2010) for the Euro-CORDEX domain were conducted including ARI and ARI + ACI (ARCI), establishing as a reference a simulation where aerosols were not included interactively (BASE). The results show that the effects of ARI and ACI on time-mean spatially averaged precipitation over the whole domain are limited. However, a spatial redistribution of precipitation occurs when the ARI and ACI processes are introduced into the model, as well do changes in the precipitation intensity regimes. The main differences with respect to the base-case simulations occur in central Europe, where a decrease in precipitation is associated with a depletion in the number of rainy days and clouds at low level (CLL). This reduction in precipitation presents a strong correlation with the ratio PM 2.5/ PM 10 , since the decrease is especially intense during those events with high values of that ratio (pointing to high levels of anthropogenic aerosols) over central Europe. The precipitation decrease occurs for all ranges of precipitation rates. On the other hand, the model produces an increase in precipitation over the eastern Mediterranean basin associated with an increase in clouds and rainy days when ACIs are implemented. Here, the change is caused by the high presence of PM 10 (low PM 2.5/ PM 10 ratios, pointing to natural aerosols). In this case, the higher amount of precipitation affects only days with low rates of precipitation. Finally, there are some disperse areas where the inclusion of aerosols leads to an increase in precipitation, especially for moderate and high precipitation rates. [ABSTRACT FROM AUTHOR]

The contract audit is an instrument facilitating the evaluation of prices offered and costs incurred in non-competitive defence contracts. In this study we analyse the degree of harmonization of contract auditing models among four European countries by means of a comparative analysis of the characteristics of contract auditing in these countries. We identify similarities and differences among the contract auditing models applied in these countries, and conclude that they do not present a high degree of harmonization of defence contract cost evaluation. [ABSTRACT FROM AUTHOR]

Aerosol-cloud interactions (ACI) represent one of the most important sources of uncertainties in climate modelling. In this sense, realistic simulations of ACI are needed for a better understanding of the complex interactions between air pollution and the climate system. This work quantifies the added value of including ACI in an online coupled climate/chemistry model (WRF-Chem, 0.44 ∘ horizontal resolution, years 2003 to 2010) in order to assess whether there is an improvement in the representation of aerosol optical depth (AOD). Modelling results for each species have been evaluated against the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis, and AOD at 675 nm has been compared to AERONET data. Results indicate that the improvements of the monthly biases are around 8% for total AOD550 when including ACI, reaching 20% for the monthly bias in AOD550 coming from dust. Moreover, the temporal representation of AOD550 largely improves (increase in the Pearson time correlation coefficients), ranging from 6% to 20% depending on the chemical species considered. The benefits from this improvement overcome the problems derived from the high computational time required in ACI simulations (eight times higher with respect to simulations not including aerosol-cloud interactions). [ABSTRACT FROM AUTHOR]