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Unsere ZieleObservations of Cirrus Clouds and Trace Gases in the Extra-Tropical UTLS by CRISTA-NF

Martin Riese (1), Katja Weigel (1), Reinhold Spang (1), Peter Preusse (1),

Lars Hoffmann (1), Friedhelm Olschewski (2), and Fred Stroh (1)

(1) Institute for Chemistry and Dynamics of the Geosphere (icg-1:Stratosphere)

(2) Bergische Universität Wuppertal, FB Mathematik und Naturwissenschaften

UTLS Workshop, NCAR, Boulder, October 21, 2009

CRISTA-NF onboard GEOPHYSICA

• Limb emission profiles [20 km to ground]• Vertical sampling and FOV = 200 m • Horizontal sampling = about 12 km

SCOUT-O3 in November 2005; SCOUT-AMMA in August 2006

Limb-radiance spectra

• Cloud Index = radiance MW1 / radiance MW2• Narrow sub-visible cirrus layers frequently encountered• Occurence frequency of thin cloud layers (< 1 km) in extra-tropics: ~20 %

MW1 MW2

CO2H2OCFC -11R

adia

nce

[W

/cm

2 sr

cm

-1]

Tan

gen

t h

eig

ht

[km

]

Wavenumber [cm-1]

November 4, 2005; 420N, 160O

Spang et al., ASR, 2008

Could observations in sub-tropics

Transfer flight from Utapao to Hyderabad

• Cloud top as well as cloud base detectable• Outflow-like layers of very low IWC (~ 0.01 ppmV)

Spang et al., ASR, 2008

CRISTA-NF trace gas observations

Wavenumber [cm-1]

• Temperature, H2O, Ozone, HNO3, CCl4, PAN (PhD work Katja Weigel)

Italy, July 29, 2006

Rad

ian

ce [

W/c

m2 sr

cm

-1]

Italy, July 29, 2006

CRISTA-NF trace gas observations

PAN [ppbv]

PAN

North NorthSouth

• Structure of enhanced PAN values above 12 km altitude in both flight directions (opposite viewing directions)• Horizontal extend > 500 km; oriented along LOS

Ozon PAN H2O

Alt

itu

de

[km

]

• Corresponding enhancement in other tropospheric trace gases (H2O, CCl4)

Time [UTC]

Alt

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de

[km

]

PAN Ozon

• Stratospheric trace gases (O3 and HNO3) also show an enhancement • This points to a strong influence of mixing

Time [UTC]

• Effects of mixing clearly show up in correlation plot! (Small FOV and favorable viewing direction)

PAN - ozone correlation

Location of mixed area

Location of mixed area

Location of mixed area

Location of mixed area

Mixed area at the extra-tropical side of the STJ !

Time [UTC]

Ozone

Alt

itu

de

[km

]

ECMWF Ozone

• Observed ozone distribution not well reproduces by ECMWF

Time [UTC]

Ozone

Alt

itu

de

[km

]

ECMWF Ozone CLaMS Ozone

• The observed structures are well reproduced by CLaMS• This is a good basis for on-going analysis

Summary and Outlook

• High resolution limb emission sounding can provide unique information on cloud and trace gas distribution in the UTLS

• CRISTA-NF observed an occurence frequency of thin (< 1km) SVC layers of about 20%.

• Trace gas structures observed over Italy (July 29, 2006) point to a strong influence of mixing.

• The structures are reasonable reproduced by CLaMS (allowing further diagnoses)

• Current limb sounders (satellite or aircraft) do not provide high-resolution 3D distribution (3rd dimension is missing).

Limb-imaging and tomographie

Source: FZJ-ZAT

GLORIA-AB on HALO (JÜLICH and KIT)

First test flight envisaged for summer 2010 !

PREMIER3D limb sounding from space

Typhoon

PREMIER

MIPAS

Sampling:0.5 km x 25 km x 50 km (dynamics mode) 0.5 km x 4 km x 8 km (clouds)