Filters

2005 - 200912010 - 20131

More filters

20192
Reset filters

Settings

Publisher: München : European Geopyhsical Union × Subject: nitrogen ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Integrated analysis of water quality in a mesoscale lowland basin
    (München : European Geopyhsical Union, 2005) Habeck, A.; Krysanova, V.; Hattermann, F.
    This article describes a modelling study on nitrogen transport from diffuse sources in the Nuthe catchment, representing a typical lowland region in the north-eastern Germany. Building on a hydrological validation performed in advance using the ecohydrological model SWIM, the nitrogen flows were simulated over a 20-year period (1981-2000). The relatively good quality of the input data, particularly for the years from 1993 to 2000, enabled the nitrogen flows to be reproduced sufficiently well, although modelling nutrient flows is always associated with a great deal of uncertainty. Subsequently, scenario calculations were carried out in order to investigate how nitrogen transport from the catchment could be further reduced. The selected scenario results with the greatest reduction of nitrogen washoff will briefly be presented in the paper.
  • Thumbnail Image
    Item
    Aerosol decadal trends - Part 2: In-situ aerosol particle number concentrations at GAW and ACTRIS stations
    (München : European Geopyhsical Union, 2013) Asmi, A.; Collaud Coen, M.; Ogren, J.A.; Andrews, E.; Sheridan, P.; Jefferson, A.; Weingartner, E.; Baltensperger, U.; Bukowiecki, N.; Lihavainen, H.; Kivekäs, N.; Asmi, E.; Aalto, P.P.; Kulmala, M.; Wiedensohler, A.; Birmili, W.; Hamed, A.; O'Dowd, C.; Jennings, S.G.; Weller, R.; Flentje, H.; Fjaeraa, A.M.; Fiebig, M.; Myhre, C.L.; Hallar, A.G.; Swietlicki, E.; Kristensson, A.; Laj, P.
    We have analysed the trends of total aerosol particle number concentrations (N) measured at long-term measurement stations involved either in the Global Atmosphere Watch (GAW) and/or EU infrastructure project ACTRIS. The sites are located in Europe, North America, Antarctica, and on Pacific Ocean islands. The majority of the sites showed clear decreasing trends both in the full-length time series, and in the intra-site comparison period of 2001–2010, especially during the winter months. Several potential driving processes for the observed trends were studied, and even though there are some similarities between N trends and air temperature changes, the most likely cause of many northern hemisphere trends was found to be decreases in the anthropogenic emissions of primary particles, SO2 or some co-emitted species. We could not find a consistent agreement between the trends of N and particle optical properties in the few stations with long time series of all of these properties. The trends of N and the proxies for cloud condensation nuclei (CCN) were generally consistent in the few European stations where the measurements were available. This work provides a useful comparison analysis for modelling studies of trends in aerosol number concentrations.