资源环境科技发展态势分析平台

Hence, this contribution aims at quantifying 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 (years 1991–2010) for the Euro-CORDEX domain have been conducted including ARI and ACI, establishing as reference a simulations where aerosols have not been included interactively (BASE).

The results show that the effects of ARI and ACI on mean spatially averaged precipitation are limited. However, a spatial redistribution of precipitation occurs when introducing the ARI and ACI processes in the model; as well as some changes in the intensity precipitation 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 low clouds. This reduction in precipitation presents a strong correlation with the ratio PM_2.5/PM₁₀, since the decrease is specially intense during those events with high values of that ratio (pointing to high levels of anthropogenic aerosols) over the aforementioned area. The precipitation decrease occurs for all ranges of precipitation rates. On the other hand, the model produces an increase in precipitation over the western Mediterranean basin associated with an increase of clouds and rainy days when ACI are implemented. Here the change is caused by the high presence of PM₁₀ (low PM_2.5/PM₁₀ ratios, pointing to natural aerosols). In this case, the higher amount of precipitation affects only to those days with low rates of precipitation. Finally, there are some disperse areas were the inclusion of aerosols leads to an increase in precipitation, specially for moderate and high precipitation rates.