Lightning NOx and impact on O3 in a high-resolution CTM

Xin Yang, Glenn Carver, Maria Russo, Scott Hosking, John Pyle

Centre for Atmospheric ScienceDepartment of Chemistry University of Cambridge

May 21th, 2009

Model information• Model: 3D chemical transport model, p-TOMCAT, forced by CMWF reanalysis

data (6hrs).

• High horizontal resolution (0.56x0.56 degree) with 31 vertical layers

• Lightning NOx=5ppbv released at UT=00 7th December in a 2x2 gridbox (12S-13S, 129E-130E) covering 2 model layers between pressure 130-190 mba (roughly 12-15km).

•

5 ppb NOx released

5ppbv NOx released

• Deep convection-related lightning could be an important NOx source, especially in the tropical region

• Our integration shows that these lightning NOx (e.g. 5 ppbv NO) in upper troposphere can increase ozone by up to 5ppbv.

• •However, we need to check if the cloud-top height method for flash/NOx production (Price and Rind 1992) is enough to create that much NO. Maybe we need a much higher production rate for deep convective cloud.

• Our current high resolution model (0.5 degree) seems can not reproduce these deep convective clouds. Need much fine resolution model•

Conclusions

Thank you!