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

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Lightning NOx and impact on O3 in a
high-resolution CTM
Xin Yang, Glenn Carver, Maria Russo, Scott
Hosking, John Pyle Centre for Atmospheric
Science Department of Chemistry University of
Cambridge May 21th, 2009
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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 NOx5ppbv released at UT00 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
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5ppbv NOx released
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Conclusions

• 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

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Thank you!