Ammonia flux has been monitored continuously since July 2008 oversemi-natural grassland at the Hungarian NitroEurope site 'Bugacpuszta'onthe Great Hungarian Plain. Results presented here are based onthe data obtained from July to September, i.e., during the vegetationperiod. The instrument used for ammonia concentration gradient measurement was a novel diode laser based photoacoustic devicecombined with preconcentration sampling (WaSul-Flux), developed atthe University of Szeged. Ammonia concentration measurements wereperformed at three different levels (0.5 m, 1.3 m and 3 m), on a cc. 30-minute accumulation interval. The three inlets were moved automaticallyto the same level (1.3 m) twice a week by a remote controlled automatedsystem to check the precision of the measurement.The turbulent flux of ammonia was calculated using the similaritytheory based on eddy covariance data of momentum, heat, water vaporand carbon dioxide fluxes (provided by a CSAT3 sonic anemometer anda LICOR-7500 open path CO2/H2O sensor), in view of the frictionvelocity (u*) and the Monin-Obukhov length scale (L). Sensitivityanalyses of ammonia flux calculation as (i) calculation of ammoniagradient, (ii) choice of universal function and (iii) application of differentgradient and profile techniques, have been investigated.The diurnal variation of the ammonia concentration and flux has alsobeen investigated. During the studied period the net daytime emission andnocturnal deposition were observed with large deviation exceeding theaverage flux values both during day and night.The daily mean ammonia concentrations were compared to datameasured at the Hungarian background air quality monitoring station (Kpuszta)̃20 km far from the Bugac-puszta site, and fairly good agreementwas found between the two datasets.
|Title of host publication||Ammonia|
|Subtitle of host publication||Structure, Biosynthesis and Functions|
|Publisher||Nova Science Publishers, Inc.|
|Number of pages||14|
|Publication status||Published - Jan 1 2012|
ASJC Scopus subject areas
- Chemical Engineering(all)