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dc.contributor.authorZwart HJMA
dc.contributor.authorHogenkamp JEM
dc.contributor.authorMennen MG
dc.contributor.authorErisman JW
dc.date.accessioned2012-12-12T23:45:50Z
dc.date.available2012-12-12T23:45:50Z
dc.date.issued1994-03-31
dc.identifier722108001
dc.identifier.urihttp://hdl.handle.net/10029/262273
dc.description.abstractAbstract niet beschikbaar
dc.description.abstractThis report deals with the performance of a monitoring system for continuous determination of SO2 and NO2 dry deposition fluxes to forests. The system consists of several meteorological instruments, gas monitors, a computer and data acquisition equipment. Fluxes of SO2 and NO2 are determined according to the gradient method and with the eddy correlation technique (only for NO2). The performance was studied from December 1991 to August 1992 both in the laboratory and in the field, at the heathland site Elspeetsche Veld next to an SO2 dry deposition system for low vegetation. The results of these experiments were used to determine the reliability of the forest system and to estimate the error in measured deposition fluxes. For SO2 the system works well. The SO2 monitors and meteorological instruments are reliable for monitoring. The average random error in SO2 fluxes and deposition velocities is 50%, based on 4-hour average gradients, and systematic errors are generally limited to 20%. For NO2 the system is less suitable. The NO2 monitors frequently show technical problems and require a lot of maintenance. The random error in the NO2 fluxes determined with the gradient method is 50% to 250% for 4-hour average gradients. Systematic errors are caused by reactions involving O3, NO and NO2, and by interferences of O3, PAN and H2O on the signal of the NO2 monitor. Nevertheless, these fluxes show approximately the same diurnal course as those obtained from a parameterization, which is based on the assumption that the surface exchange of NO2 is mainly determined by stomatal behaviour. NO2 fluxes determined with the eddy correlation were systematically underestimated. This method must be further investigated. After the performance study the system was installed at the site Speulder forest (in November 1992), where it was operated, further improved and extended with instruments for determination of NH3 fluxes.
dc.description.sponsorshipDGM/LE
dc.format.extent107 p
dc.language.isoen
dc.relation.ispartofRIVM Rapport 722108001
dc.relation.urlhttp://www.rivm.nl/bibliotheek/rapporten/722108001.html
dc.subject07nl
dc.subjectdroge depositienl
dc.subjectmetennl
dc.subjectevaluatienl
dc.subjectmonitoringnl
dc.subjectbos zwaveldioxidenl
dc.subjectstikstofdioxidenl
dc.subjectammoniaknl
dc.subjectdry depositionen
dc.subjectmeasurementsen
dc.subjectevaluationen
dc.subjectmonitoringen
dc.subjectforestsen
dc.subjectsulphur dioxidesen
dc.subjectnitrogen dioxidesen
dc.subjectammoniaen
dc.subjectso2en
dc.subjectnh3en
dc.subjectno2en
dc.titlePerformance of a monitoring system for measurement of SO2 and NO2 dry deposition fluxes to a foresten
dc.title.alternative[Onderzoek naar het functioneren van een opstelling voor het meten van droge depositiefluxen van SO2 en NO2 boven bos.]nl
dc.typeReport
dc.contributor.departmentLLO
dc.date.updated2012-12-12T23:45:51Z
html.description.abstractAbstract niet beschikbaar
html.description.abstractThis report deals with the performance of a monitoring system for continuous determination of SO2 and NO2 dry deposition fluxes to forests. The system consists of several meteorological instruments, gas monitors, a computer and data acquisition equipment. Fluxes of SO2 and NO2 are determined according to the gradient method and with the eddy correlation technique (only for NO2). The performance was studied from December 1991 to August 1992 both in the laboratory and in the field, at the heathland site Elspeetsche Veld next to an SO2 dry deposition system for low vegetation. The results of these experiments were used to determine the reliability of the forest system and to estimate the error in measured deposition fluxes. For SO2 the system works well. The SO2 monitors and meteorological instruments are reliable for monitoring. The average random error in SO2 fluxes and deposition velocities is 50%, based on 4-hour average gradients, and systematic errors are generally limited to 20%. For NO2 the system is less suitable. The NO2 monitors frequently show technical problems and require a lot of maintenance. The random error in the NO2 fluxes determined with the gradient method is 50% to 250% for 4-hour average gradients. Systematic errors are caused by reactions involving O3, NO and NO2, and by interferences of O3, PAN and H2O on the signal of the NO2 monitor. Nevertheless, these fluxes show approximately the same diurnal course as those obtained from a parameterization, which is based on the assumption that the surface exchange of NO2 is mainly determined by stomatal behaviour. NO2 fluxes determined with the eddy correlation were systematically underestimated. This method must be further investigated. After the performance study the system was installed at the site Speulder forest (in November 1992), where it was operated, further improved and extended with instruments for determination of NH3 fluxes.


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