Effects of Initial and Boundary Values of Reactive Nitrogen Compounds and Hydrocarbons on the Ozone Concentration in the Free Troposphere
The initialisation and the treatment of the boundary conditions of a mesoscale chemistry-transport-model, covering a limited area, are of great importance. The choice of the initial and boundary values can significantly influence the results of a simulation, so that they should be determined as well as possible (NAPAP, 1991). For this reason it is important to provide realistic conditions, if possible derived from current measurements. Unfortunately trace species in the troposphere, especially in the middle and upper free troposphere, are not observed continuously so that relatively little is known about background concentrations. Usually there are no current observations available which can be used as input data for episodic simulations. The available measurements show a high variability in the concentrations of the trace species. To analyse and to quantify the effects of a variation of the initial and boundary values for model results sensitivity studies were carried out with the European Air Pollution Dispersion modeling system (EURAD) using different initial and boundary scenarios. Therefore the literature has been reviewed and a set of initial and boundary values were derived based on available observation data. With regard to the formation of ozone the focus was set on reactive nitrogen species and hydrocarbons, which are important photooxidant precursor species. First a set of simulations with different scenarios representing free tropospheric conditions is calculated with a boxmodel version of the EURAD model in order to determine the non-linear dependencies of the gas phase chemistry. Furthermore a sensitivity study with the full three dimensional model is performed for a summersmog episode.
KeywordsEurope Ozone Hydrocarbon Advection Photolysis
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- Feldmann, H., Ebel, A., Mass, H., Memmesheimer, M., and Jakobs, H.J., 1995, Analysis of polluted air masses effecting the area of Eastern Germany during a SANA episode, In: A. Ebel and N. Moussiopoulos, eds., Air Polution III, volume 4: Observation and simulation of air pollution: results from SANA and EUMAC (EUROTRAC), pp. 95-102, Southampton, CMP.Google Scholar
- Feldmann, H., Hass, H., Memmesheimer, M., and Jakobs, H.J., 1996, Budgets of atmospheric sulfer for East Germany based on meso-of-scale simulations, Meteorol. Zeitschrift 5:193–204.Google Scholar
- Grell, G.A., Dudhia, J., and Stauffer, D.R., 1994, A description of the fifth-generation Penn State/NCAR mesoscale model (MM5), Technical note TN-398+STR, NCAR, Boulder, Colorado.Google Scholar
- Hass, H., 1991, Description of the eurad chemistry-transport-model version2 (CTM2), In: A. Ebel, F. Neubauer, and P. Speth, eds., Mitteilungen aus dem Institut für Geophysik und Meteorologie der Universität zu Köln, volume 83, Universität Köln, Köln.Google Scholar
- Hass, H., Ebel, A., Feldmann, H., and Memmesheimer, M., 1993, Evaluation studies with a regional chemical transport model (EURAD) using air quality data from the EMEP monitoring network, Atmos. Environ. 27A(6):867–887.Google Scholar
- Memmesheimer, M., Ebel, A., and Roemer, M., 1997, Budget calculations for ozone and its precursors: seasonal and episodic features based on model simulations, J. Atmos. Chem. in press.Google Scholar
- Memmesheimer, M., Tippke, J., Ebel, A., Hass, H., Jacobs, H.J., and Laube, M., 1991, On the use of EMEP emission inventories for European scale air pollution modeling with the EURAD model, In: J. Pankrath, ed., EMEP workshop on photooxidant modelling for long-range transport in relation to abatement strategies, pp. 307-324, Umweltbundesamt, Berlin.Google Scholar
- NAPAP, 1991, Acid deposition: state of science and technology, volume 1, emissions, atmospheric processes, and deposition, U.S. National Acid Precipitation Assesment Program, Washington, DC.Google Scholar
- Singh, H.B., Herlth, D., Kolyer, R., Salas, L., Bradshaw, J.D., Sandholm, S.T., Davis, D.D., Crawford, J., Kondo, Y., Koike, M., Talbot, R., Gregory, G.L., Sachse, G.W., Browell, E., Blake, D.R., Rowland, F.S., Newell, R., Merrill, J., Heikes, B., Liu, S.C., Crutzen, P.J., and Kanakidou, M., 1996, Reactive nitrogen and ozone over the western Pacific: distribution, partitioning, and sources, J. Geophys. Res. 101(D1):1793–1808.CrossRefGoogle Scholar