The Extratropical UTLS: Observations, Concepts and Future Directions.
1 COST 723 WG1 Meeting 1 October 6-7, 2003 University of Bern, CH Availability of UTLS relevant...
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Transcript of 1 COST 723 WG1 Meeting 1 October 6-7, 2003 University of Bern, CH Availability of UTLS relevant...
COST 723 WG1 Meeting 1October 6-7, 2003
University of Bern, CH
Availability of UTLS relevant SCIAMACHY data
C. von Savigny, A. Rozanov, A. Ladtstätter, A. Richter, K.-U. Eichmann, and John P. Burrows
Institute of Environmental Physics and Remote SensingIUP/ife UB
Department 1Physics/Electrical Engineering
Institute of Environmental Physics andInstitute of Remote Sensing
University of Bremen
Outline
• SCIAMACHY – instrument features• Deliverable data: - Ozone - NO2, SO2, BrO, Cloud information• Under Development: - H2O
The SCIAMACHY Instrument
Features:
• UV/Vis/NIR grating spectrometers:240 - 2380 nm
• Moderate spectral resolution:0.2 – 1.5 nm
• 8 channels: 8000 spectral points
• Measurements:– Atmospheric radiance:
scattered, reflected and transmitted sunlight
– Extraterrestrial solar irradiance
– Lunar radiance
SCIAMACHY Measurement Geometries
• Typical spatial resolution in nadir: 30 km x 60 km
• Global coverage for limb and nadir within 6 days
• Special feature: nadir-limb matching
SCIAMACHY Limb Geometry
• Vertical resolution: 2.6 km• Horizontal resolution in azimuth
direction: 240 km (120 km min.), 960 km swath
• Horizontal resolution in flight direction: approx. 400 km
• Observation optimised to match limb with nadir measurements
• Duration of Limb sequence: 60 sec
Spectral Coverage and detectable Species
Retrieval from Limb Measurements
• 300 –370 nm: Ozone
Useful height range: 5—50 kmAbove 12 km all information comes from the measurementNo smoothing
Averaging Kernels Limb
Ozone, comparison with Ozone Sondes
24 July 2002, Ny-Alesund 6 November 2002, Hohenpeissenberg
C.von SavignyA. Rozanov
Comparison: SCIAMACHY - SHADOZ-Measurements
SHADOZ (Southern Hemisphere Additional Ozonsondes), A. Thompson et al. 2000
0
10
20
30
40
50
60
0 1x1012 2x1012 3x1012 4x1012 5x1012
SHADOZ-Station (Natal): 14.11.2002
O3 [molec/cm 3]
Alti
tude
[km
]
SHADOZ Sonde-Profile SCIAMACHY Limb-Profile
A. Ladtstätter-Weissenmeyer
Validation timespan: September / October 2002
Colocation criteria: tangent point within of 500 km
HALOE on UARS POAM III on SPOT-4
Validation of stratospheric Ozone Profiles
Limb MeasurementsOptimal Estimation
C.von SavignyA. Bracher
Clouds detected from the VIS vs. NIR
Latitude: 11.7° N
Jump in radiance at about 15 km is due to clouds (Mie scattering)
Color ratio 1090/750 nm
C.von Savigny
10
20
30
40
0.1 0.2 0.3 0.4 0.5
Tropospheric clouds
Stratospheric background aerosol
PSC
PSC
Orbit 02796, 12-SEP-2002
a) Lat: 32oS, Long: 344o
b) Lat: 47oS, Long: 338o
c) Lat: 69oS, Long: 320o
d) Lat: 75oS, Long: 304o
Color index (1090 nm / 750 nm) [a.u.]
Tang
ent h
eigh
t [km
]
Employ color-index: CI = LR(1090 nm) / LR(750 nm)
Detection of PSCs by Color Index
background
C.von Savigny
Water Vapour Signatures
• Limb spectra from 0 to 42 km• Every 3 km• Clear signaturesOf H2O in the UTLS region
Trace gases from Nadir Measurements
SCIAMACHY SO2
Summary
• Scientific Retrieval of SCIAMACHY UV/vis limb results works nicely for O3, NO2, BrO
• Ozone is measureable down to about 14 km in the tropics and 10 km at higher latitudes
• Clouds are the limiting factor for the retrieval of the UTLS region
• Water vapour retrieval is currently under development
• Scientific DOAS analysis of SCIAMACHY UV/vis nadir results works nicely for NO2, SO2, and O3 UV
• Results for NO2 and SO2 are very promising and show the potential of SCIAMACHY for tropospheric measurements