Herman G.J. Smit, COST 723, Bern, 6-7 Oct, 2003 1 MOZAIC-Data, Particularly the Use of Water Vapor Data for UTLS-Studies and the Urgent Need for Integrated

Herman G.J. Smit, COST 723, Bern, 6-7 Oct , 2003

1

MOZAIC-Data, Particularly the Use of Water Vapor Data for UTLS-Studies and the Urgent Need for

Integrated Data Sets of Ground Based, Airborne and Satellite Observations of Humidity

Herman G.J. Smit Research Centre Jülich, Institute for Chemisty and Dynamics of the Geosphere: Troposphere (ICG-II),

52428 Juelich, Germany (Email: [email protected])

H 2 O -S e n s o r

AIRCRAFTSKIN

SENSORSRH: HUMICAP-HT : PT100

DEICINGHEATER

BOUNDARY LAYERSCONTROL HOLES

RIGHT ANGLEPRODUCESPARTICLE

SEPARATION


2

• Five Passenger A340-aircraft, operated by 4 European Airlines on scheduled flights• Quasi continuous sampling between 0 and 12 km altitude• 2,500 Flights per year; 175,000 hours of O3 and H2O data since August 1994

• CO and NOY since 2001

MOZAIC: Measurement of Ozone and Water Vapor by Airbus In-Service AircraftPassenger Aircraft as Observation Platform for Atmospheric Research


3

MOZAIC: Aircraft Sampling Inlet


4

H 2 O -S e n s o r

AIRCRAFTSKIN

SENSORSRH: HUMICAP-HT : PT100

DEICINGHEATER

BOUNDARY LAYERSCONTROL HOLES

RIGHT ANGLEPRODUCESPARTICLE

SEPARATION

MOZAIC- Humidity Sampling Technics: Rosemount Probe and Humidity Device


5

MOZAIC Humidity Device: Performance and Quality Assurance

Regular calibration (every 500 flight hours)

In environmental simulation chamber

Against Lyman ()- fluorescence hygrometer

Under realistic flight conditions of humidity, temperature and pressure

Evaluation of two year record of pre- and post-flight calibrations Results agree well with in-flight inter- comparisons [Helten et al., J.Geophys.Res.1999]

-60 -40 -20 0 20S ta tic A ir T e m p e r a tu r e

0

2

4

6

8

10

Abs

.Err

or o

f R

el.H

umi.

[% R

H]

1 2 9 6 3 0

A ltitu d e [k m ]

A ll D a ta 1 9 9 9 /2 0 0 0

In: Helten et al., J.Geophys.Res., 1998


6

MOZAIC Relative Humidity in Upper Troposphere (UT) over North Atlantic

0 25 50 75 100 125 150 175R elative H um idity [% , Ice]

0

2

4

6

8

10

Pro

pabi

lity

[%

]

ECMW F

MOZAIC

40N-60N

• MOZAIC provided the first

climatology of humidity in the UT • Large variability in time and

space

-20

0

20

40

60

La

titu

de

5102030405060708090100

Jan

95

Jan

96

Jan

97

Jan

98

Jan

99

Jan

00

• UT is much wetter than

assumed before MOZAIC • ECMWF does not reproduce

the ice super saturation

%

Control of Humidity in UT?? Long Term Changes ??


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MOZAIC: Ice Super Saturation in Upper Troposphere

• 15-30% of the UT is ice super saturated (ISS)• Small scale phenomena (X < 200 km; Z < 2 km)

SAGE II / % Sub-visible Cirrus

MO

ZA

IC/

% Ic

eS

uper

satu

rati

on

SAGE II / % Sub-visible Cirrus

MO

ZA

IC/

% Ic

eS

uper

satu

rati

on

• Strong correlation of ISS with sub-visible cirrus clouds• Important for cirrus cloud formation and radiative balance

Causes of ice super-saturation and the interaction with clouds ??


8

Ice

Liquid

0

2

4

6

8

10

12

Pro

babi

lity

[%]

0 25 50 75 100 125 150 175R elative H um idity [% ]

00N-20N

Ice

Liquid

0

2

4

6

8

10

12

Pro

babi

lity

[%]

0 25 50 75 100 125 150 175R elative H um id ity [% ]

20N-30N

Ice

Liquid

0

2

4

6

8

10

Pro

babi

lity

[%]


30N-40N

Ice

Liquid

0

2

4

6

8

10

Pro

babi

lity

[%]


40N-60N

MOZAIC: Distribution Relative Humidity in UT over AtlanticZ = 9-12 km, PV < 2.0pvu, 10W-70W, Aug 1994 - June 2000


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Concept of Evolution of UTH in Cb-Outflow

oceanSST (convection)

dee

p c

on

vect

ion

Advection &Subsidence

CTT < 240K METEOSAT

RHAC

TAC

O3AC

(Backward Trajectories byMeteo France)

SST (aircraft)

low O3 (10-20 ppb)


10

MOZAIC: Evolution RHI-distribution in outflow of Cb-Convection (1)

•10-20 flights/month

100% 100%


11

Fluglinien

51

51,5

52

52,5

53

13 13,5 14 14,5 15geogr. Länge

geo

g.r

Bre

ite

Lindenberg

Frakf-Seoul

Seuol-Frankf

Wien-Atlanta

Fank-Lo

Latitude

Long

itude Lindenberg

RS80-Humicap-A: Comparison UTH with MOZAIC

Radiosounding station Lindenberg at 14.1oE, 52.2oN Coindence MOZAIC and Radiosonde

In time: Less than 1 hourIn space: 2 degree latitude and longitude altitude range: ZAC +/-250m

Flight Tracks


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Vergleich Flugzeug-Radiosonde

y = 1.107x + 6.5575

y = 0.9306x + 10.325

0

20

40

60

80

100

0 20 40 60 80 100

rH[%] Radiosonde

rH[%

] M

OZ

AIC U_min

U_max

Linear (U_min)

Linear (U_max)

RH by Radiosonde (RS80-A, Corrected after MOL) [%]

RH

by

MO

ZA

IC [

%]

RS80-Humicap-A: Comparison UTH with MOZAIC

RS80-A are corrected at low temperatures after method of normalized frequencies developed by Leiterer at MOL/DWD:: http://www.metoffice.com/research/interproj/radiosonde/reports/index.html


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Outlook: Upper Tropospheric Humidity Scientific Objectives

Seasonal variations of UTH in tropics, sub-tropics and mid-latitude & UTH control mechanims:

Influence of convection and subsidence on UTH Impact of (sub-visible) cirrus clouds on UTH-control Sensitivity of UTH to surface and UT-temperature Origin and control of ice super saturation

---------------------------------------------------------------------------

Scale analysis of UTH-variations

Long term changes of UTH (MOZAIC, radio sondes)


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Integration of UTH-data through validation and assimilation of: Satellites (e.g. ENVISAT, SAGE-III , AIRS etc.) Aircraft (MOZAIC + Research A/Cs) Radiosondes Groundbased (e.g.LIDAR, FTIR)

Benefits through improvement of: Weather analysis and forecasting (ECMWF) Climate: UTH-Feedback & Meso scale and Gen.Circ. Models UTH and its control mechanisms Atmospheric Chemistry: Physico-Chemical Models

Outlook: Integrated Network of UTH-Observations


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MOZAIC: Acknowledgements

Air France

Lufthansa (2 AC‘s)

Sabena

Austrian Airlines

Acknowledgement to::

European Commission for

Funding (50%)Airlines for no charge of:

Carrying MOZAIC-

instruments Maintainance at airports

Documents

Herman G.J. Smit, COST 723, Bern, 6-7 Oct, 2003 1 MOZAIC-Data, Particularly the Use of Water Vapor Data for UTLS-Studies and the Urgent Need for Integrated