j. puķīte, s. kühl, t. deutschmann, w. wilms-grabe, c....

Satellite Satellite Group:Group:http://satellitehttp://satellite.iup.uni.iup.uni--heidelberg.deheidelberg.de

Institute for Environmental PhysicsInstitute for Environmental PhysicsUniversity of HeidelbergUniversity of Heidelberg

AtmosphericAtmospheric ScienceScience ConferenceConferenceMaMayy 88 ––1212, 2006 ; , 2006 ; FrascatiFrascati

Retrieval of Stratospheric Retrieval of Stratospheric Trace Gases Trace Gases

(O(O33, NO, NO22, BrO, BrO andand OClO)OClO)from SCIAMACHY Limb from SCIAMACHY Limb

MeasurementsMeasurementsJ. J. PuPuķīķītete, S. , S. KKüühlhl, T. , T. DeutschmannDeutschmann, , W. WilmsW. Wilms--Grabe, Grabe,

C. VonC. Von Friedeburg, Friedeburg, U. Platt andU. Platt andTT. Wagner. Wagner




Motivation

X + O3 XO + O2XO + hv X + O---------------------------

O3 O + O2

X = Cl, Br, NOXO = ClO, BrO, NO2

BrO + ClOOClO + Br

Scientific Assessment of Ozone DepletionWMO, 2003

Motivation Geometry Retrieval Validation First Results Conclusion & Outlook





SCIAMACHY is first satellite instrument that observes BrO in limb geometry

First that observes BrO, OClO, NO2 in limb on global scale

Application of Heidelberg DOAS algorithm for limb geometry

Two step approach (separate DOAS and RTM)

Application of Monte Carlo RTM (Tracy II)

Motivation




Measured atmospheric

spectrum

Measured reference spectrum

SCD retrieval by DOAS

Radiative transfer

modeling

A-priori constraints

Profile retrieval by linear optimal estimation

Absorption cross

sections

Two step approachDOAS DOAS => => Slant column densitiesSlant column densities

RTM => Box AMF factorsRTM => Box AMF factors

Box Air Mass Factors

}} => Profiles by OE=> Profiles by OE





• Tangent height range: -3.3 to 100 km

• Scan width 240 km x 4 pixels

• Tangent height step size: ~3.3 km

• Vertical FOV: ~2.6 km

• horizontal resolution in azimuth: 240 km (120 km min.)

• horizontal resolution in flight direction: ~ 400 km

SCIAMACHY Limb Geometry

Source: IFE, Uni Bremen





320 340 360 380 400 4201E11

1E12

1E13

0 20

40

60 kmPho

tons

/ s

m2 n

m s

r

Wavelength (nm)

Intensities in UVMotivation Geometry Retrieval Validation First Results Conclusion & Outlook




363 – 391 nmO3 223K, NO2 220K, OClOO4, Ring1/I0 , Eta, Zeta

OClODOAS analysis of SCIAMACHY limb spectra





BrO

337 – 357 nm O3 223K,

O3 243K, BrONO2, Ring1/I0 Eta, Zeta

DOAS analysis of SCIAMACHY limb spectraMotivation Geometry Retrieval Validation First Results Conclusion & Outlook




Slant Column Densities – NO2

orbit 2509 – 23.08.2002

7

15

0

Limb states for orbit 2509S

CD

, cm

-2


0 5 10 15 20 25 30 35 40 45 50tangent height, km




Estimation Theory

SCD = F (C·∆h) = F (VCD)

C = VCD /∆h = (AMF) –1 * SCD /∆h

y = F(x) + ε

y = y0 + K0 (x-x0) + ε= K0 x + ε

y : Measurement vectorx : state vectorε : ErrorF : Forward model

F : AMF

x0 : a priori state vectory0 : calculated by y0 = F(x0) = K0 x0


1 1 1 1 10 0 0 0 0 0ˆ ( ) ( )T

y yx K S K S K S y S x− − − − −= + +S0 : a priori covarianceSy : measurement covariance

Rodgers, 2000




)()(),()( jerroriparameterjiAMFjtMeasuremen +⋅=∑

RTM Tracy II (Tim Deutschmann, 2006) used)

Forward modelMotivation Geometry Retrieval Validation First Results Conclusion & Outlook

Visualization of photon paths by Monte Carlo RTM model

Tracy II

• Rayleigh scattering

• ground scattering

• photon paths

)(),(),(

iVCDjiSCDjiAMF =




High elevations, LOS transparent atmosphere

LOS elevation 39 km τ (340.25 nm)=0.23 TP


Monte Carlo RTM modelingTracy - II

Low elevations, large optical density along LOS

LOS elevation 15 km τ (340.25 nm)=7.4

LOS elevation 9 km τ (340.25 nm)=25

TP

TP




Box Air Mass Factors (AMF) 340 nm (BrO)


Tangent height, km





tangent height, km tangent height, km




NO2

BrO

O3

OClO

Averaging KernelsMotivation Geometry Retrieval Validation First Results Conclusion & Outlook




Validation NO2Aire sur l’Adour (44°N France), 9.10.2003, balloon ascent

Butz et al., ACP, 2006


Kiruna (68°N Sweden), 24.03.2004, balloon ascent




Balloon profiles from Dorf et al., ACP, 2006

Validation BrO

15

20

25

30

35

0 1x107 2x107 3x107

Balloon SCIA

Aire sur l Adour09/10/2003, Orbit 8407

Number density [molec/cm3]

Alti

tude

[km

]

15

20

25

30

35

0 1x107 2x107 3x107

Balloon SCIA

Aire sur l Adour, France 44 N10/10/2003, Orbit 8421


Alti

tude

[km

]

15

20

25

30

35

-1x107 0 1x107 2x107 3x107 4x107 5x107

Balloon SCIA

Kiruna, Sweden 68N24/03/2003, Orbit 5558


Alti

tude

[km

]

, France, 44 N


Validation of BrO with ground based DOAS: please visit poster of Francois Hendrick




SCIA OClO10-12 Jan 03

ODIN ClO13-14 Jan 03

OClOmolec/cm3

ClO at 475 K (19 km) OClO at 18 km

Validation OClOMotivation Geometry Retrieval Validation First Results Conclusion & Outlook

Urban et al., GRL 2003




SCIA OClO17-19 Jan 03

ODIN ClO19 Jan 03

OClOmolec/cm3

Validation OClOMotivation Geometry Retrieval Validation First Results Conclusion & Outlook

Urban et al., GRL 2003




24.08.2004 O3

NO2 24.08.2004

OClO 24.08.2004

24.08.2004 BrO

Motivation Geometry Retrieval Validation First Results Conclusion & Outlook30.09.2004 O3

30.09.2004 NO2

OClO 30.09.2004

BrO 30.09.2004




17.04.2004

15.03.2004

18.02.2004

15.05.2004

15.06.2004

15.07.2004

14.08.2004

15.09.2004

15.10.2004

15.11.2004

15.12.2004

15.01.2005

latitude latitude

Annual cycle of BrO – longitudinal averageMotivation Geometry Retrieval Validation First Results Conclusion & Outlook




OClO Jan 2005Motivation Geometry Retrieval Validation First Results Conclusion & Outlook

7-9 Jan 10-12 Jan

25-27 Jan

13-15 Jan

16-18 Jan 21-23 Jan

cm-3




Conclusion

Two step approach (DOAS, RTM combined by optimal estimation) allows to investigate effect of spectroscopy and radiative transfer on profiles separatelyResults are consistent with expectations from stratospheric chemistry

Global retrieval of profiles of general trace gases

Good agreement with expectations and validation results


please visit poster of Sven Kühl nr. 72




Outlooko Evaluate larger datasetso Sensitivity studieso Improve Retrieval (DOAS, RTM,

Climatologies for T, p and a priori)o Scientific analysis of data:

Reservoirs, Comparison to model studies, o OClO: Occultation measurementso Comparison with nadir & ground

measurements.o Participation in SCIAVALIG, BOOST (Bromine

Oxide in the lOwer STratosphere) campaigns.


j. puķīte, s. kühl, t. deutschmann, w. wilms-grabe, c....

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