title: Low cost measurements of nitrogen and sulphur dry deposition velocities at a semi-alpine site: gradient measurements and a comparison with deposition model estimates.
abstract: The conditional time averaged gradient method was used to measure air-surface exchange of nitrogen and sulphur compounds at a semi-alpine site in Southern Norway. Dry deposition velocities were then obtained from the bi-weekly concentration gradient measurements. Annual deposition velocities were found to be 1.4, 11.8 and 4.0 mm s(-1) for NH3, HNO3 and SO2, respectively, if all data were included, and to be 10.8, 11.8 and 13.0 mm s(-1), respectively, if only positive values were included. Measured deposition velocities were compared to two sets of values estimated from a big-leaf dry deposition module applying to two different land types (short grass and forbs, and tundra), driven by measured micrometeorological parameters. The deposition module gives reasonable values for this site throughout the year, but does not reproduce the large variability as shown in the measured data. No apparent seasonal variations were found from either measurements or module estimates due to the very low productivity of the studied area.
authors: Norwegian Institute for Air Research (NILU), Department of Atmosphere and Climate, Polar Environment Centre, 9296 Tromsø, Norway. lrh@nilu.no
authors: Lars R
authors: LR
authors: Hole
authors: Sibyl H
authors: SH
authors: Brunner
authors: Jan Erik
authors: JE
authors: Hanssen
authors: Leiming
authors: L
authors: Zhang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis; D003365:Costs and Cost Analysis; D004784:Environmental Monitoring / Q000191:economics / Q000379:methods*; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis*; D009608:Nitrous Acid; D009664:Norway; D011891:Rain; D012621:Seasons; D013455:Sulfur / Q000032:analysis*; D013458:Sulfur Dioxide / Q000032:analysis
chemical_list: D000393:Air Pollutants; D013458:Sulfur Dioxide; D013455:Sulfur; D000641:Ammonia; D009584:Nitrogen; D009608:Nitrous Acid