Understanding Emissions of Ammonia from Buildings and Application of Fertilizers: An Example from Poland

A Europe-wide dynamic ammonia (NH3) emissions model has been applied for one of the large agricultural countries in Europe, and its sensitivity on the distribution of emissions among different agricultural functions was analyzed by comparing with observed ammonia concentrations and by implementing all scenarios in a CTM model. The results suggest that the dynamic emission model is most sensitive to emission from animal manure, in particular how this is connected to national regulations. In contrast, the model is most robust with respect to emission from buildings and storage. To do this, we obtained activity information on agricultural operations at the sub-national level for Poland, information about infrastructure on storages and current regulations on manure practice from Polish authorities. The information was implemented in the existing emission model and was connected directly with the NWP calculations from the Weather Research and Forecasting model (WRF-ARW). The model was used to calculate four emission scenarios with high spatial (5 km x 5 km) and temporal resolution (3h) for the entire year 2010. In the four scenarios, we have compared the European-wide default model settings against: 1) a scenario that focuses on emission from agricultural buildings, 2) the existing emission method used in WRF-Chem in Poland, and 3) a scenario that takes into account Polish infrastructure and agricultural regulations. The ammonia emission was implemented into the chemical transport model FRAME and modelled ammonia concentrations was compared with measurements. The results suggest that the default setting in the dynamic model is an improvement compared to a non-dynamical emission profile. The results also show that further improvements can be obtained on the national scale by replacing the default information on manure practice with information that is connected with local practice and national regulations. Implementing a dynamical approach for simulation of ammonia emission is a viable objective for all CTM models that continue to use fixed emission profiles. Such models should handle ammonia emissions in a similar way to other climate dependent emissions (e.g. Biogenic Volatile Organic Compounds). Our results, compared with previous results from the DEHM and the GEOS-CHEM models, suggest that implementing dynamical approaches improves simulations in general even in areas with limited information about location of the agricultural fields, livestock and agricultural production methods such as Poland

Operational mapping of atmospheric nitrogen deposition to the Baltic Sea

International audienceA new model system for mapping and forecasting nitrogen deposition to the Baltic Sea has been developed. The system is based on the Lagrangian variable scale transport-chemistry model ACDEP (Atmospheric Chemistry and Deposition model), and aims at delivering deposition estimates to be used as input to marine ecosystem models. The system is tested by comparison of model results to measurements from monitoring stations around the Baltic Sea. The comparison shows that observed annual mean ambient air concentrations and wet depositions are well reproduced by the model. Diurnal mean concentrations of NHx (sum of NH3 and NH4+) and NO2 are fairly well reproduced, whereas concentrations of total nitrate (sum of HNO3 and NO3-) are somewhat overestimated. Wet depositions of nitrate and ammonia are fairly well described for annual mean values, whereas the discrepancy is high for the monthly mean values and the wet depositions are rather poorly described concerning the diurnal mean values. The model calculations show that the annual atmospheric nitrogen deposition has a pronounced south--north gradient with depositions in the range about 1.0 T N km-2 in the south and 0.2 T N km-2 in the north. The results show that in 1999 the maximum diurnal mean deposition to the Danish waters appeared during the summer in the algae growth season. For the northern parts of the Baltic the highest depositions were distributed over most of the year. Total deposition to the Baltic Sea was for the year 1999 estimated to 318 kT N for an area of 464 406 km2 equivalent to an average deposition of 684 kg N/km2

Projected change in atmospheric nitrogen deposition to the Baltic Sea towards 2020

The ecological status of the Baltic Sea has for many years been affected by the high input of both waterborne and airborne nutrients. The focus here is on the airborne input of nitrogen (N) and the projected changes in this input, assuming the new National Emission Ceilings directive (NEC-II), currently under negotiation in the EU, is fulfilled towards the year 2020. With a set of scenario simulations, the Danish Eulerian Hemispheric Model (DEHM) has been used to estimate the development in nitrogen deposition based on present day meteorology combined with present day (2007) or future (2020) anthropogenic emissions. Applying a so-called tagging method in the DEHM model, the contribution from ship traffic and from each of the nine countries with coastlines to the Baltic Sea has been assessed. The annual deposition to the Baltic Sea is estimated to 203 k tonnes N for the present day scenario (2007) and 165 k tonnes N in the 2020 scenario, giving a projected reduction of 38 k tonnes N in the annual load in 2020. This equals a decline in nitrogen deposition of 19%. The results from 20 model runs using the tagging method show that of the total nitrogen deposition in 2007, 52% came from emissions within the bordering countries. By 2020, this is projected to decrease to 48%. For some countries the projected decrease in nitrogen deposition arising from the implementation of the NEC-II directive will contribute significantly to compliance with the reductions agreed on in the provisional reduction targets of the Baltic Sea Action Plan. This underlines the importance of including projections like the current in future updates of the Baltic Sea Action Plan

Sentinel-2 satellite and HYSPLIT model suggest that local cereal harvesting substantially contribute to peak Alternaria spore concentrations

Alternaria is a human/animal allergen and plant/animal pathogen. Cereal harvesting emits a large amount of Alternaria spores into the atmosphere. However, estimating the peak spore periods and source areas from large areas is often a challenge because of insufficient observation stations. The purpose of this study was to examine, using remote sensing and an atmospheric transport and dispersion model, the contribution of cereal harvesting to peak Alternaria spore concentrations. Daily Alternaria spores were collected using Hirst-type traps in 12 sites in Europe for the period 2016-2018. Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectory and dispersion model was integrated with Sentinel-2 satellite imagery, Corine Land Cover 2018 (CLC2018) and Eurostat cereal data 2016 to map the Alternaria spore peaks and source areas in the 12 sites. Ground truth harvest data, collected at Worcester, UK, in 2018, and meteorological data were used to determine any effect of cereal harvesting and weather on peak spore concentrations. The results showed that the Sentinel-2 satellite detected agricultural areas that underwent intensive harvesting and this coincided with a rapid increase of Alternaria spore concentrations. Furthermore, local agricultural areas cultivated with cereals were the main sources of the peak Alternaria spore concentrations in all the study sites. Remote agricultural and non-agricultural sources, to a lesser extent, contributed to the peak spore concentrations at some sites, e.g. Borstel, Leicester and Worcester. Temperature during the harvesting periods (July and August) was found to significantly contribute to the peak spore concentrations. Overall, the study showed that it is possible to use Sentinel-2 satellite data alongside atmospheric transport and dispersion models to estimate periods of peak Alternaria spore concentrations and sources at a continental scale. This approach can be replicated for other bioaerosols that affect human health, agriculture and forestry

Identification of Potential Sources of Airborne Olea Pollen in the Southwest Iberian Peninsula

This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009–2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (south-western Spain) and Évora (south-eastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources during conditions with slow air mass movements. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies that examine sources and the atmospheric transport of pollen are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop