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OWP5: SCOUT balloons(Stratosphere-Climate links with emphasis on the UTLS)

Andrew Robinson

Centre for Atmospheric Science, Cambridge University, Cambridge, UK

adr22@cam.ac.uk

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Cambridge Centre for Atmospheric ScienceHalocarbon Measurement Group

A. D. Robinson (1), B. Gostlow (1), N. R. P. Harris (1,2), J. A. Pyle (1,3)

(1) Centre for Atmospheric Science, Cambridge University, Cambridge, UK(2) European Ozone Research Coordinating Unit, Cambridge, UK

(3) NCAS-ACMSU, Cambridge University, Cambridge, UK

adr22@cam.ac.uk

http://www.atm.ch.cam.ac.uk/~halocarbon/

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Content

Introduction: halocarbon group

Balloon options in AMMA (Summer 2006)

Slow descent balloons

Example results from HIBISCUS

Short lived tracers with Dirac

Conclusion

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Halocarbon group instruments

DESCARTES grab samplers

DIRAC in situ isothermalGC-ECD

DIRAC in situ programmedGC-ECD

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3SF balloon (24 Feb 2004, Bauru, Brazil)

Balloon options in AMMA / SCOUT O3

Ballooning phase of SCOUT O3 from West Africa Summer 2006 (current plan)

Two balloon flights funded (plans for at least 2 more)

3SF (3000 m3) balloons with slow night-time descent through TTL (preferred option)

10ZL (10000 m3) balloons with parachute descent from 25-30 km

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3SF balloon flight data (13 Feb 2003, Bauru, Brazil)

Slow descent balloons

3SF balloon model data (courtesy: G. Letrenne, CNES)

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Air temperature, ºC-100 -80 -60 -40 -20 0 20 40

Pot

entia

l te

mpe

ratu

re, K

300

350

400

450

Lapse rate, K km-1-12 -10 -8 -6 -4 -2 0 2 4 6 8 10

[CFC-11] pptv150 200 250 300

[O3] ppb0 200 400 600 800 1000

TTL

Long lived tracer profile (DIRAC CFC-11)

No significant drop below 430 K, 19 km(vertical transport very slow above this level?)

Ozone increase begins inside the TTL

Slightly higher CFC-11 values around 360 K(horizontal transport?)

Ozone data courtesy of Graeme Hansford

Example results: HIBISCUS (24 Feb 2004)

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[CFC-113] pptv

0 20 40 60 80

Pot

entia

l tem

pera

ture

, K

340

360

380

400

[O3] ppb

0 200 400 600 800 1000

[O3] ppb

0 200 400 600 800 1000

[Choroform] pptv

0 2 4 6 8 10

[O3] ppb

0 200 400 600 800 1000

Pot

entia

l tem

pera

ture

, K

340

360

380

400

[Dibromomethane] pptv

0.0 0.1 0.2 0.3 0.4

ozone

CFC-113

chloroform

dibromomethane

SF1 20040216

SF2 20040213

SF3 20040226

Example results: HIBISCUS (TTL)

Long lived tracer (CFC-113): low inter-flight variabilitynear zero gradient across TTL

Short lived tracers:more intra-flight / inter-flight variabilitylarger gradient across TTL(except chloroform on SF2)

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Short lived tracers with Dirac

Target short lived tracers for AMMA / SCOUT O3:

Biogenic: CH3I (~7d), CHBr3 (~26d), CH2Br2 (~120d), CH3Br ?Industrial: C2HCl3 (~5d), CHCl3(~150d), C2Cl4(~100d)

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Conclusions

AMMA / SCOUT O3 aiming for summer 2006

Slow descent balloons flights (preferred option)

Two flights funded (2 more?)

Dirac preferred instrument

Target gases: short lived (some long lived)

Lifetime range: 5 days to 80 years

Acknowledgements: Many thanks to NERC, EC (HIBISCUS), TrroCCiBras