mitglied der helmholtz-gemeinschaft unsere ziele observations of cirrus clouds and trace gases in...
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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
itu
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)