ENVISAT VALIDATION AT TROPICS

J. P.POMMEREAU, A. GARNIER, F. GOUTAIL, F. BORCHIService d ’Aéronomie CNRS, Verrières le Buisson, France A. HERTZOG and F. VIALLaboratoire de Météorologie Dynamique, Palaiseau, France

N. R. P. HARRIS, J. PYLE, R. L. JONES, A. ROBINSON, G. HANSFORDDept of Chemistry, University of Cambridge

A. BUIVANInstituto de Pesquisas MeteorologicasBauru, SP, Brazil

G. LETRENNECNES Toulouse, France

ESABC PARIS 8 Nov

2002

OUTLINE

SAOZ short and long duration balloon flights at the tropics : example of past results

Plan for February - Mars 2003

PAST EXPERIENCE IN BRAZIL

• Nov 1997 EC Stratospheric Regular Soundings Four short duration 10 ZL flights SAOZ, SAOZ-BRO, DESCARTES, LABS, OPC

• Nov 2000 and February 2001 CNES technical MIR flights + two ZL

IPMet balloon facility at Bauru-SP (Brazil, 22°S)

• IPMet : Institute of Meteorological Research of the State University of Sao Paulo (UNESP)Bauru

Sao Paulo

HIBISCUS

Meteorological supportWeather radarRadiosondes stationBalloon launch facilityAirport

Stratospheric Regular SoundingNovember 1997

302010010

6 mol.cm

-3

BrO

642010

12 mol.cm

-3

Ozone

30

25

20

15

10

5

0-80 -40 0

(°C)

Temperature

420

109 mol.cm

-3

NO2

SAOZ / SAOZ-BrO flight

February 2001 : SAOZ-MIR test flight

Launched from Bauru (Brazil), Feb 13, 2001

34 days flight, 2 circum-navigation

Validation of measurements at Reunion Island (lidar, sondes)

Recovered in Argentina

Bauru Reunion

Is.Salta

SAOZ-MIR test flight

Instrumentation (60 kg total) :

3 independent payloads

- SAMBA: GPS, T, P, IR radiometer, control and safety

- SAOZ : Solar occultation Uv-Visible spectrometer: O3, NO2, O2, O4, H2O, atmospheric extinction

- RUMBA : GPS, T, high temporal resolution Pressure

Ozone variability

40

35

30

25

20

15

10

5

0543210

Number Density 1012 mol / cm3

O3

SunriseSunsetMean

40

30

20

10

0543210

Ozone (x1012

mol/cm3)

Ozonesondes La Reunion Feb - 300 mLidar La Reunion 23 FebMIR Indian Ocean: Individual profiles Average

Overpass over Reunion Island

SAOZ-MIR, lidar and sondes

Longitudinal variability

• 3% in LS above 20 km (little influence of horizontal transport)

• 30% in UT strong horizontal exchange (highly pv correlated)

Nitrogen Dioxide

40

35

30

25

20

15

10

5

03210

Number density 109 mol / cm3

NO2

Sunrise Sunset

1.00.50.0-0.5

(SS-SR)/SS

NO2 Diurnal Change

• Secondary maximum at 22-24 km

• Highly variable in both UT and LS

• Minimum concentration and diurnal variation at Tropopause

Requires:• Local source of NOx Electric discharges? Precipitation of charged particles in Atlantic anomaly?

• NOx gas phase chemistry different from currently known

• Heterogneous NOx/NOy reactions at tropopause

Example of Satellite Validation

MIR and HALOE variability along latitude circle

24

22

20

18

16

14

12

10100806040200

Ozone variability (std dev %)

MIR

MIR

HALOE

MIR without transport

OZONE24

22

20

18

16

14

12

10806040200

NO2 variability at sunrise (std dev %)

Haloe

MIR

MIR Horiz.Transport removed

NO2

Tropopause Tropopause

HALOE O3 and NO2 perturbed by clouds below 22 kmMeasurements not reliable below tropopause

35

30

25

20

15

10

5

06420

Extinction at 550nm(10-3 km-1)

Opaque clouds(Ci, sub-vis Ci)

Sunrise, Sunset

Tropopause Haze

Rayleigh Extinction

Clouds

Observations

Optical Extinction at 550 nm

32

28

24

20

16

10

2

3

4

56

100

AfricaAustralia AustraliaS. America

300

250

200

150

100

50706560555045

Global IR Radiometer

-80

-60

-40

-20

Day 2001

Global IR

Radiometer

300

250

200

150

100

50150 100 50 0 -50 -100 -150

LongitudeS. America Africa Australia

20

15

10

5

0

Tropopause Height

Cirrus and sub-visual cirrus

Higher and thicker above continental areas

Permanent ultra-thin tropopause Haze

35

30

25

20

15

10

5

0210

Mie Extinct 550 nm(10-3 km-1)

-100 -80 -60 -40Temperature(°C)

Tropopause Haze

Sunrise, Sunset

- Ubiquitous at T<200K- 1 part./Cc (r=1µm)

• Size distribution ?

• Formation ?

• Photochemical impact ?

Electrical discharges in the stratosphere

• Frequency over high convective area ?

• Impact on stratospheric chemistry ?

Electrical impact of payloads and balloon around 20-22 km

60 km

20 km

Blue Jet at AreciboPasko et al., Nature, March 02

LIS Flashes DJF

ENVISAT VALIDATION CAMPAIGN

FEBRUARY 2003

TWO 10 ZL BALLOONS (ONE SUNSET, ONE SUNRISE)

SAOZ (O3, NO2, H2O, clouds), SAOZ-UV (BrO, OClO ? CH2O?), DIRAC GC (N2O, CFC), DESCARTES (SLS, O3 SSS, H2O SAW, Micro-Lidar

TWO MIR (2 months autonomy)

Met, Global IR radiometer, lightning detector. 1st : regular SAOZ (O3, NO2, trop. H2O, extinction at 550 nm); 2nd: SAOZ H2O (O3, NO2, strat H2O, extinction at 1 µm)

RADIOSONDES

RS-90, O3 SSS, O3 ECC, H2O SAW, H2O H-Humicap