SAOZ NOx and LightningJ. P. Pommereau and F. Goutail

Ground-based SAOZ in Bauru since 1995

Short duration small balloon flights

MIR long duration flights

Modelling

Further work

SAOZ Spectrometer at IPMet in Bauru since 1995Network for Detection of Stratospheric Change (NDSC)

complementary station

O3 and NO2 columns at Bauru since 1995

350

300

250

200

Vertical Column (DU)

O3

Morning Evening

95 96 97 98 99 00 01 02 03

8

6

4

2

0

Vertical Column (1E15 mol/cm2)

95 96 97 98 99 00 01 02

NO 2

03

O3

NO2

Parameters Slope of correlation

Amplitude (1e15)

Amplitude (%)

Seasonal cycle 0.956 ± 0.02 1.38 38 ENSO shifted by 4 m. 0.10 ± 0.0 2 0.40 11 QBO 10hPa sh 2 mo -0.0007 ± 1e-4 0.45 12 Magnetic activity Kp 0.001 ± 0.003 0.05 1.3 10.7cm Flux sh 2 m. 5e-5 ± 4e-5 0.09 2.5

Most important parameters Season Small influence ENSO and QBO (10 hPa) No influence of Solar flux and Kp Average Residual <0.001%, max 4%

NO2 evening columns above BAURU

NO2 evening columns above BAURU

95 96 97 98 99 00 01 02 03

5

4

3

2

1

NO2 Evening

-0.8

-0.4

0.0

0.4

0.8

-0.8

-0.4

0.0

0.4

0.8

96 97 98 99 00 01 02 03

Residual NO2 Evening

40

35

30

25

20

15

10

53.02.52.01.51.00.50.0

NO2 (x109 mol/cm3)

Morning Evening

40

35

30

25

20

15

10

53.02.52.01.51.00.50.0

Concentration (x109 mol/cm3)

NO2

MorningEvening

ZL 18 Feb Morning

ZL 23 Feb Evening

2001 2003

MIR-SAOZ 2004

Lightning ?

(larger NO2 in the morning ?)

NOy mid-lat ?Local prod by blue-jets ?

350 300 250 200 150 100 50 0

25

20

15

10

5

0

2000

1500

1000

500

0

60

20

20

20 0

0 0

-20

-20

-30

-30

-50

NO2 DEVIATION (%)

∆Z 360-340 KLIS Flashes

NO2 MIR-SAOZ 2001 20°S

% deviation from zonal mean

Maximum in UT over continental convection

Minimum over Maritime areas

Correlated with O3 STE ?

?

MOZART Modelled lightning and NOx production at the Equator JFM (NOx production over continental convection only)

Continental and Maritime convection of different nature

Lightning Imaging Sensor onboard TRMM (DJF)

350 300 250 200 150 100 50 0

25

20

15

10

5

0

15 0

NO2 MIR-SAOZ 2003 20°S

% deviation from zonal mean

Correlated with O3 STE ?

?

High lightning activity at launch

MIR-SAOZ 2003

MIR-SAOZ 2004

Lightning ?

(larger NO2 in the morning ?)

NOy mid-lat ?Local prod by blue-jets ?

2004

2004

As 2001 and 2003

UT / TTLLow over maritime convection (as 2001)

High over Africa (as 2001)Limited over South America (less than 2001)

? 20 km maxbut at diff loc

12-14 March

MIR over Africa

High Lightning activity

20-23 March

MIR over Amazonia

Low Lightning activity

Summary NO2 Sources (I)

Local production vs transportRemoval of H transport by PV correlation

Production by lightning in UT and TTLMaximum column onn strong lightning daysMaximum up to 200 ppt at 15 km , 100 ppt at 12 km highly correlated to lightning activity over continental convective areas Minimum 10-20 ppt over maritime convective areas

Further workMIR Correlation with LIS flashes during 5 days prior to MIR overpass How much NOx produced by lightning: comparison to model simulations, ajustment of parametrisation. LMDz / TOMCAT modelling in progress over Bauru as well as at MIR location

Summary NO2 Sources (2)

Max NO2 0.2-0.3 ppb at 20-22 km at longitude depending on year

STE ? Local production in LS by blue-jets followed by QBO dependent transport ?

Further work

Characterisation: Source in Reprobus and Mimosa Chem ?

Mechanism: MIPLASMO box trajectory ?