acvt-gbmcd subgroup gomos ozone profiles, analysis of comparison with gmbcd datasets
DESCRIPTION
ACVT-GBMCD subgroup GOMOS ozone profiles, analysis of comparison with GMBCD datasets (bright/dark, star magnitude, star temperature). Yasjka Meijer, RIVM [email protected]. Validation Team O 3 profiles. Validation teamPI-nameInstituteInstrument AO 153S. PalSAAI/MSCLidar - PowerPoint PPT PresentationTRANSCRIPT
Page 1Envisat Validation Workshop, ACVT-GBMCD, GOMOS O3(r) 12/12/2002
ACVT-GBMCD subgroup
GOMOS ozone profiles, analysis of comparison with GMBCD datasets
(bright/dark, star magnitude, star temperature)
Yasjka Meijer, RIVM
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Validation Team O3 profiles
Validation team PI-name InstituteInstrument
AO 153 S. Pal SAAI/MSC LidarAO 158 J.-C. Lambert BIRAMicrowave/lidar/sondes AO 179 A. Matthews NIWA Microwave/sondesAO 191 T. Blumenstock INTA FTIRAO 300 D. De Muer RMI Sondes AO 360 P. Keckhut CNRS Lidar AO 429 E. Kyro FMISondesAO 1103 A. Petritoli ISAC SondesAO 9003 D. Swart RIVM Lidar
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Intercomparison of Ozone Profiles
Geolocation criteria:
lidar (< 24 hrs, 1000 km) sonde (< 24 hrs, 1000 km) microwave radiometer (< 4 hrs, 1000 km)
GOMOS data:
from ACRI prototype processor added solar zenith angle at tangent point
GBMCD data:
collocations provided by AO-teams all files available from NILU database all data converted to ozone number density vs altitude
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Geolocation of GOMOS & GBMCD data
Lidar Sonde Microwave FTIRToronto Scoresbysund Payern KirunaLauder Hohenpeissenberg LauderAlomar Sodankyla Mauna LoaTable Mountain Payern Table MountainMauna Loa UccleHohenpeissenberg LauderObs. Haute Prov.
57 39 35 0
Total collocated GOMOS-GBMCD paired profiles: 226 • no altitude overlap: - 13• missing files GOMOS: - 82• available for analysis 131
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Example 1
Lauder lidar
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Example 2
Toronto lidar
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Example 3
Uccle sonde
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Important GOMOS parameters
Sun position (SZA) dark (110o-180o) twilight (90o-110o) bright (0o-90o)
Star temperature (K) hot (7,000-100,000) cold (1,000-7,000)
Star magnitude (MV) strong (-2 to 1) weak (1 to 5)
Less signal from weaker stars
More straylight
Less UV in colder stars
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LIDAR measurements vs GOMOS
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All data
Lidar
N = 57
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BRIGHT
Lidar
N = 4
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TWILIGHT
Lidar
N = 13
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DARK
Lidar
N = 40
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DARK
STRONG
Lidar
N = 5
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weak
DARK
Lidar
N = 35
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COLD
DARK
Lidar
N = 19
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HOT
DARK
Lidar
N = 21
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Conclusions vs LIDAR:
bright limb ozone profiles: poor results
twilight limb ozone profiles: better than bright limb, but still large deviations (cause to be determined)
dark limb ozone profiles: good results no systematic biases between 18-45 km no clear influence of star magnitude or temperature
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SONDE measurements vs GOMOS
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All data
Sonde
N = 39
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BRIGHT
Sonde
N = 26
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DARK
Sonde
N = 13
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Only 1 strong STAR (of 13), with MV<1
Sonde
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COLD
DARK
Sonde
N = 9
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HOT
DARK
Sonde
N = 4
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Conclusions vs SONDE:
bright limb ozone profiles: poor results
twilight limb ozone profiles: no cases
dark limb ozone profiles: good results small systematic bias of 5-10% between 18-35 km (GOMOS lower) star magnitude: no info star temperature: below 22 km cold better than hot and above vice versa(?, more statistics needed)
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MICROWAVE measurements vs GOMOS
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All data
Microwave
N = 35
Note: lower mesosphere included
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BRIGHT
Microwave
N = 23
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DARK
Microwave
N = 12
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NO strong STARS, with MV<1
Microwave
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COLD
DARK
Microwave
N = 4
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HOT
DARK
Microwave
N = 8
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Conclusions vs MICROWAVE:
bright limb ozone profiles: poor results
twilight limb ozone profiles: no cases
dark limb ozone profiles: (all stars) 20-45 km bias within 20% (cold stars) 45-65 km : poor results (hot stars) 45-65 km bias within 20% (hot stars) 45-65 km significant non-random bias suggests possibility for improvement star magnitude: no info
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All instrumentscompared to GOMOS
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All data
All instruments
N = 131
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BRIGHT
All instruments
N = 53
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BRIGHT
STRONG
All instruments
N = 9
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DARK
All instruments
N = 65
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DARK
STRONG
All instruments
N = 6
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weak
DARK
All instruments
N = 59
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COLD
DARK
All instruments
N = 32
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HOT
DARK
All instruments
N = 33
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Conclusions vs all GBMCD instruments:
bright limb ozone profiles: only for bright (MV<1) stars and only above 30 km GOMOS lower by 10 to 15% (30-50 km)
twilight limb ozone profiles: needs further research
dark limb ozone profiles: star magnitude: no clear influence below 18 km: poor results 18-45 km: bias 5 to 10% (all stars) 45-65 km : cold stars: poor results
hot stars: bias within 20%, significant non-random bias suggests possibility for improvement