The effects of lightning-produced NOx and its vertical distribution on atmospheric chemistry: sensitivity simulations with MATCH-MPIC

[摘要] The impact of different assumptions concerning the source magnitudeas well asthe vertical placement of lightning-produced nitrogen oxides is studied usingtheglobal chemistry transport model MATCH-MPIC. The responses of NO_x,O₃, OH, HNO₃ and peroxyacetyl-nitrate (PAN) are investigated. A markedsensitivity to both parameters is found. NO_x burdens globally can beenhanced by up to 100% depending on the vertical placement and source magnitudestrength. In all cases, the largest enhancements occur in the tropical uppertroposphere, where lifetimes of most trace gases are longer and where they thusbecome more susceptible to long-range transport by large-scale circulationpatterns.Comparison with observations indicatethat 0 and 20 Tg(N)/yrproduction rates of NO_x from lightning are too low and toohigh, respectively. However, no single intermediate production rateor vertical distribution can be singled out as best fitting the observations,due to the large scatter in the datasets. Thisunderscores the need forfurther measurement campaigns in key regions, such as the tropical continents.

[学科分类] 大气科学