1. Lightning-Produced Nitrogen Oxides during ACTIVE: what have we learned thus far? Lorenzo Labrador, Geraint Vaughan and the ACTIVE team (lorenzo.labrador@manchester.ac.uk) SEAES, University of Manchester.

2. LINET stroke time series, ACTIVE campaign Total ic cg Mini-monsoon Pre-monsoon Monsoon Monsoon-break Suppressed monsoon MCS

3. Lightning-produced NOx in Hector storms, pre-monsoon 16/11/2005 Egrett’s flight track, LINET lightning strokes Average in-cloud NO x enhancement value = 2.5 ppbv 16/11/2005 Egrett’s altitude profile, NO x, CO and cloud particles LINET- detected strokes in storm ≥ 10KA = 832 (24.5% of storm’s total)

4. Lightning-produced NOx in Hector storms, monsoon break 16/11/2005 Egrett’s flight track, LINET lightning strokes Average in-cloud NO x enhancement value = 1.16 ppbv 10/02/2002 AE27 Egrett’s altitude profile, NO x, CO and cloud particles LINET- detected strokes in storm ≥ 10KA = 1188(20.9% of storm’s total)

5. Lightning-NOx production F ltnox = Χ ltnox M (N) /M (air) ρ air (v a – v s ) Δ x Δ z P ltnox = F ltnox /R LINET (R LINET /R LIS )-> P ltnox = F ltnox /R LIS ; GL tNOx = P ltnox x Global flash rate AE04 = P ltnox = F ltnox /R LIS = 1.69 kg(NO) flash -1 AE04 GL tNOx = 2.34 Tg yr -1 AE27 = P ltnox = F ltnox /R LIS = 0.234 kg(NO) flash -1 AE27 GL tNOx = 0.32 Tg yr -1

6. Lightning-produced NO x in monsoon convection 22/01/2005 Egrett’s flight track, LINET lightning strokes, 00:00-23:59 UTC 22/01/2005 Egrett’s altitude profile, NO x, CO and cloud particles Average in-cloud NO x enhancement value = 984 ppt Storm sampled produced only 9 lightning strokes and only 17% of that day’s strokes had been produced by the time the flight ended. So, where did the NO x in the spikes come from? 22/01/2005 Egrett’s flight track, LINET lightning strokes, 00:00-10:00 UTC (end of flight) Average out-of-cloud NO x enhancement value =720 ppt

7. AE18’s 3 rd NOx spike (741 pptv NOx) AE18’s 7 th NOx spike (1570 pptv NOx) 5-day backward-trajectories suggest that airmass sampled may have accrued NO x during transit over convectively-active region 22/01/06; flight AE18’s 5-day backward trajectories

8. Conclusions The tropics play a crucial role in the production and redistribution of Lightning-produced NO x LtNO x production in Hector storms on a par with tropical continental convection elsewhere (Brazil), although further studies are warranted Lightning-NO X in monsoon convection more significant than previously thought

9. NO: Vertical profiles

12. Conclussions