Atmospheric nitrogen dynamics in Hesse, Germany: Creating the data base. 2. Atmospheric concentrations of ammonia, its reaction partners and products at Linden

Keywords:

Abstract:

Within the Hessian atmospheric nitrogen dynamics project, concentration measurements of gaseous ammonia, nitrous acid, nitric acid and sulphur dioxide as well as of ammonium, nitrate, sulphate, chloride and sodium in particles (PM3) were made at Linden near Giessen, Hesse, between November 2001 and December 2004. The primary goal was the establishment of a data set that could be combined with a soil vegetation atmosphere transfer (SVAT) model to assess the vertical fluxes. Weekly measurements of mean day and night concentrations were made using denuder-filter equipment. In order to obtain information about the typical diurnal variation of these concentrations, another programme was established at the site of the Federal Agricultural Research Centre near Braunschweig. Here, a set of eight samplers was used to derive correction factors for three-hourly periods.<o:p></o:p></span></p>
<p><span style="font-size: 10pt; font-family: "Times New Roman";">When compared with other measurements in <st1:country-region w:st="on">Germany</st1:country-region> and <st1:place w:st="on">Europe</st1:place>, concentrations indicated a moderately polluted countryside situation. As usual, ammonia concentrations followed the annual pattern of agricultural emissions. Nitric acid concentrations reflected the overall photochemical activity. <st1:place w:st="on"><st1:city w:st="on">Sulphur</st1:city></st1:place> dioxide emissions are determined by energy consumption and peak in winter. The spatial and temporal variabilities of the concentrations of nitrogen and sulphur species in atmospheric particles were definitely smaller than for gases. Both ammonium and nitrate concentrations exhibited a maximum in spring and seemed to be related with ammonia emissions. Chloride and sodium concentrations indicated their common origin in sea spray.</span></p>
<p> </p>