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C A R I B I CCivil Aircraft for Regular Investigation of the atmosphere Based on an Instrument

Container

Luftfrachtcontainer gefüllt mit wissenschaftlichen

Instrumenten, eingebaut für einzelne Messflüge

1 – 2 Messflüge pro Monat (24 – 48 Flugstunden)

11 beteiligte europäische Institute (Koordination: MPI-C, Mainz)

MPI für Chemie, Mainz

IMK, Karlsruhe

IFT, Leipzig

DLR, Oberpfaffenhofen

GKSS, Geesthacht

Universität Heidelberg

UEA, Norwich, UK

University Lund, Sweden

KNMI, de Bilt, The Netherlands

CEA/CNRS, Paris, France

Universität Bern, Schweiz

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CARIBIC II

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CARIBIC II ContainerPTR-MS O3 H2O

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>4nm18-180nm

CARIBIC II maiden flight 13/14 Dec 2004Frankfurt - Buenos Aires

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CARIBIC II: Status & Zukunft

Status

Anfang Dezember 2004: Fluggenehmigung Airbus A340 & Container durch LBA

13/14. Dezember: Erstflug nach Buenos Aires/Santiago

Logistik vollständig (high-loader, LKW, test equipment etc.)

Einlass funktioniert mechanisch & elektrisch

Airbus „power management“ erlaubt noch keine Aufwärmphase vor Flug

(kleine) Softwareprobleme bei Master PC

einige Instrumente noch nicht vollständig funktionsbereit

Zukunft

Zweitflug: 18/19. Februar 2005 nach Sao Paulo/Santiago (Parallelflug

TROCCINOX)

Danach 1-2 Messflüge (25-60 h) pro Monat

anvisierte Flugziele: Südamerika, Südafrika, Ost Asien, Ostküste Nordamerika

2005: beheben aller technischer Probleme, keine neuen Geräte

Veröffentlichungen & Anträge schreiben

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Tunable Diode Laser Absorption Spectroscopy (TDLAS)

zur Messung von D/H, 17O/16O und 18O/16O in H2O

Lambert-Beer

σ(ν)

Absorptionsquerschnitt

N Molekül

Konzentration

L Absorptionlänge

Laser Mess-Zelle (p,T const.)

Referenz-Zelle ([c] const.)

Sample Detektor

Reiner Absorber

Referenz Detektor

)(

)0(10)()0()( log)exp(

ll I

IODlNII

Aufeinander abgestimmt

Christoph Dyroff

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Erste Messspektren bei 1.37μm, L~40 cm

0.10 nm

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What we can learn from isotope

measurements

in the atmosphere?

central motivation of atmospheric isotope studies is to better

understand the budget of the examined trace constituents, i.e.

to quantify source/sink strenghts, chemical processing,

photolysis rates, transport fluxes etc.

- notation

e.g.18O(H2O) = (Rsample / RV-SMOW – 1) * 1000 o/oo

with R = 18O/16O

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Isotope fractionation

processes

Phase transitions

e.g. vapour pressure isotope effect

Chemical reactions

Kinetic fractionation

diffusion, transport

Photolysis rates

(Radioactive decay)

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Isotopes measured in the atmosphere

Standard Mean Ocean Water (SMOW) D/H 155.76 · 10-6

17O/16O 379.9 18O/16O 2005.2

PeeDee Belemnite (PDB) 13C/12C 1118017O/16O 385.918O/16O 2067.2

Air (AIR) 15N/14N 3676.5

isotope ratio trace gas

hydrogen D/H (T/H) H2O, CH4, H2

carbon 13C/12C (14C/12C) CO2, CH4, CO (C2H6, C3H8, …)

oxygen 17O/16O, 18O/16O H2O, CO2, CO, N2O, O3 (NO2, …)

nitrogen 15N/14N N2O (NH3, NH4, NO2, NO3, …)

(10Be/7Be, 34S/32S)

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Isotope fractionation effects

solar radiation

CHEMICALREACTIONS

condensation+

sublimation

stratospherictroposphericExchange

(STE)

effusion+

deposition

biosphere mankind

ablation+

evaporation

meteorites,asteriodes,

comets

Tropopause

8 – 16 km

CHEMICALREACTIONS

volcanism

sedimentation

dissolutioncondensationevaporation

gas-particletransformation

condensation+

evaporation

sedimentation + rainout

ices

terrestrialradiation

boundary layer

1 – 2 km

free

troposphere

stratosphere

PHOTOLYSIS

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17O – 18O plot

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O3 formation: rate coefficient ratios

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„Transfer“ of isotope anomaly

O3

SO42-

S(IV)aq

N2O

CONMHC

NO

NO2

at ground

NO3

O3

O(1D) CO2

OH

H2O

HNO3

H2O

H

O

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Processes controlling H2O isotopomers

vapor pressureisotope effect

kineticfractionation

ice lofting

T R A N S P O R T

T R A N S P O R T + C H E M I S T R Y

MIF

MDF

CH4 oxidation

H2O HOx,, Ox

HDO = - (600-800)o/oo

H218O = - (100-160)o/oo

H217O = 0o/oo (= 17O – 0.52 * 18O)

17 km

8 km

23 km

30 km

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Isotope fractionation of H2O

= 1 – fractionation factorfractionation

Raleigh fractionation

dRcondensate = (T) · Rgas Rgas(t) = Rgas(0)·f-1

vapour pressure istope effect (vpie)

vpie

kinetic fractionation

kin = S(T) / [vpie · D/Di ·(S(T)-1) + 1] S(T)

oversaturation

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H2O isotope observations at ground

Meteoric Water Line (MWL) (in precipitation)

D(H2O) = 8.0 · 18O(H2O) + 8.6 (in per mil)

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IAEA / WMO networkfor H2O isotope composition in monthly

precipitation

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Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

Apr

Mar

Feb

Jan

-170

-160

-150

-140

-130

-120

-110

-23 -22 -21 -20 -19 -18 -17 -16 -15

18O [‰]

D [

‰]

D = 7.81 18O + 8.3

slope = 7.75

Local MWL in

water vapour

at

Heidelberg

1981-2000

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H2O isotope observations at ground

Meteoric Water Line (MWL) (in precipitation)

D(H2O) = 8.0 · 18O(H2O) + 8.6 (in per mil)

Temperature effect

D(H2O) = 8.0 · 18O(H2O) + 8.6 (in per mil)

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18O(H2O) vs. T in water vapour at Heidelberg

1981-2000

18O = 0.43 T - 23.22

18O = 0,80 T - 24,39

18O = 0,39 T - 23,03

-30

-25

-20

-15

-10

-10 0 10 20 30

T [°C]

O

[‰

]

-30

-25

-20

-15

-10

winter

summer

spring & autumn

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H2O isotope observations

Zahn, 2001

airborne sampling at 50-80°N, DI-IRMS measurement in the laboratory

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H2O isotope observations

Webster et al., Science, Dec. 2003

Kuang et al., GRL, 2003

Simulated Isotope Profiles

O isotopism of OH controls dO(H2O) !

> 99 % of all H2O molecules produced in the middle

atmosphere are due to H abstraction by OH:

CH4 + OH H2O + CH3

CH2O + OH H2O + HCO

HCl + OH H2O + Cl

OH + OH H2O + O(3P)

H2 + OH H2O + H

What reactions form new OH bonds ?

X + O2 HOx + Y

X + O3 HOx + Y

X + O(1D) HOx + Y

O exchange: OHx + O2, NO, H2O

Origin of O of freshly produced OH