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Federal Department of Home Affairs FDHA
Federal Office of Meteorology and Climatology MeteoSwiss
Analysis of the long-term profile ozonemeasurements of MeteoSwiss
E. Maillard Barras, R. Stübi, MeteoSwiss, Payerne
• Payerne ozone sounding series
• Arosa Umkehr series
• Microwave SOMORA ozone series
2SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Ozone sounding from Payerne
2002: Brewer-Mast to ECC sonde1 instrumental change
vertical resolution: 100 mozone profiles from 0 to ~32 km
time resolution: 3 profiles/weekcontinuously operated since 1968
(1966)
• The BM data series have been described in Jeannet et al. (2007),• Ozone balloon soundings at Payerne (Switzerland): Reevaluation of the time series 1967–2002
and trend analysis, J. Geophys. Res., 112, D11302, doi:10.1029/2005JD006862.
• The transition from BM to ECC has been described in Stübi et al. (2008), • In-flight comparison of Brewer-Mast and electrochemical concentration cell ozonesondes, J.
Geophys. Res., 113, D13302, doi:10.1029/2007JD009091
• Comparison of the series with:
• Hohenpeissenberg BM series
• Jungfraujoch high alpine station data
3SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Transition BM to ECC sondes: annual cycles
BM sondes
ECC sondes
• Annual cycles over “last 7 years of
BM ” and “first 7 years of ECC”
• No significant difference
between BM and ECC periods
4SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Tropospheric annual cycles: Payerne vs. MOHp
0 2 4 6 8 10 12
20
30
40
50
Pressure: 900 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 850 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 800 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 700 hPa
0 2 4 6 8 10 122
03
04
05
0
Pressure: 650 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 600 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 500 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 400 hPa
0 2 4 6 8 10 12
20
30
40
50
Pressure: 300 hPa
ECCBMMoHp
5SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Coincident data: Sondes vs. Alpine station JFJ
40
50
60
70
Time
Ozo
ne
[p
pb
]
1990 1995 2000 2005
20 years / monthly mean
ECCBM
Troposphere, Jungfraujoch alt. ~3600 m
6SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Laboratory controlled parameters: bg, high O3, …
5%
1.8 nb
7SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
QC parameters: pump flow rate, correction factor
7%
• Agreement with an independent
ozone column measurement:
1.0 +/- 0.2
• Ozone is proportional to flow rate
• Stability of the production
8SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Ozone trends 1970-1995 vs. 1996-2009
Jeannet et al.(2007), JGR,2005JD006862
9SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
• First order transfer functions for
ECC sondes from field campaigns
=> correcting the data (+/- 2%) for
changes of provider / solution conc.
• Difference 0.5 % => 1.0 %: 5% up to
25 km + add 1% / 2km above
• Difference SPC-1% and ENSCI-
0.5%: not significant (1%)
• Difference ENSCI => SPC with 1%:
3% till 25km + add 1.5% / 2 km
above.
New JOSIE campaign 2009-2010 to
check the recent ECC production.
Correction for change of solution conc.
05
10
15
20
25
30
Altitude [
km
]
KI_1.0 - KI_0.5 / KI_0.5 [%]
0 2 4 6 8 10 12
1000
500
100
50
30
15
Pre
ssure
[hP
a]
05
10
15
20
25
30
Altitude [
km
]
KI_1.0 - KI_0.5 / KI_0.5 [%]
0 2 4 6 8 10 12
1000
500
100
50
30
15
Pre
ssure
[hP
a]
0.8
10SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
• Mean ozone column from SCIAMACHY overpasses
• Mean ozone column from last 7 years of O3-sonding (NAI-std) + conc. correction / back-ground correction
Correction for change of sol. conc. at Nairobi
SCI NAI-std NAI-ib NAI-conc NAI-sync SCI-syn
22
02
40
26
02
80
30
03
20
34
0
Ozo
ne
co
lum
n [D
U]
std
Ib
conc
SCI
conc. +t-coinc.
11SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Umkehr by Dobson sun spectrophotometer
1988: D15 to D511 instrumental change
vertical resolution: 10-15 kmozone profiles from 10 to 50 km
time resolution: 2 prof./day (sr and ss)continuously operated since 1956
(1966)
• Retrieval of ozone profiles: umkv8 of Irina Petropavlovskikh based on OEM by Rodgersdescribed in GRL, VOL. 32, L16808, doi:10.1029/2005GL023323, 2005
• Quality control by redundant measurements
D 051
55 60 65 70 75 80 85 90 95
Solar zenith angle
N v
alu
es
55 60 65 70 75 80 85 90 95
1960 1970 1980 1990 2000
10
20
30
40
50
Altitud
e[k
m]
DU: 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
12SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Umkehr by Dobson: N-values QC ...
Instrument change: D15 to D51
13SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Umkehr by Dobson: O3 time series ...L6: 16hPa – 8 hPa
L7: 8hPa – 4 hPa
14SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Umkehr by Dobson: intercomparison results
• GAW report No. 180: Towards a Better Knowledge of Umkehr Measurements: A Detailed Study of Data from Thirteen Dobson Intercomparisons, I. Petropavlovskikh, R. D. Evans, G. L. Carbaugh, E. Maillard and R. Stubi
15SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Ozone microwave radiometer SOMORA
• Retrieval of ozone profiles: ARTS/Qpack based on OEM described in• ERIKSSON, P., et al, 2005, Journal of Quantitative Spectroscopy & Radiative
Transfer, 91, 47–64
• Redundancy with GROMOS radiometer at University of Bern (1995 - now)
2005 : front-end change
2009 : spectrometer change from AOS
to FFT
2 major instrumental changes
vertical resolution: 8 -15 kmozone profiles from 20 to 65 km
time resolution: 30 minutescontinuously operated since 2000
16SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
SOMORA: contribution function and errors
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
error [ ]
alt
itu
de
[k
m]
Error [% of profile]
Alt
itud
e[k
m]
obs error
smo error
tot error
17SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
SOMORA QC: System temperature
1
)*(
−
−=
y
yTcThTsys UoffsetUc
UoffsetUhy
−
−=with
18SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
SOMORA: monthly mean ozone time series
June 2001, mixerreparation
May 2005, front-endchange
Sept 2009, spectrometerchange
19SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
SOMORA spectrometer change: AOS to FFT
AOS 2009 FFT 2009 AOS 2008
Time [1year, 2008 / 2009]
6 hPa ~35 km
8.4 hPa ~31.3 km
12.5 hPa ~28.8 km
6 hPa ~35 km
8.4 hPa ~31.3 km
12.5 hPa ~28.8 km
20SPARC/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, January 25-27 2011
Merging SOMORA and soundings: example
SOMORA measurement errorbelow 20 km is important and the measurement contribution at the altitude range shouldbe reduced to minimum.At this altitude, radiosoundingmeasures ozone with a superior precision.
By combining both profiles weget an ozone profile withreliable values from groundto 60 km.
Consider the radiosoundingas an a priori and retrieveSOMORA ozone profile withan exclusive weight on radiosounding below 25 km
