SAG‐Ozone Ozone Measurements by the Global

Atmosphere Watch (GAW) of World Meteorological Organization (WMO)

Johannes Staehelin (et al.) Institute for Atmospheric Science

Swiss Federal Institute of Technology Zurich, Switzerland

Presentation Work of Scientific Advisory Group for Ozone of GAW/WMO:

Classical activities (mostly “Advise”) of SAG‐ozone:

1. Column ozone measurements:

1.1 Dobson

1.2 Brewer

2. Ozone profile measurements: Ozone sonde

3. World Ozone and Ultraviolet Data Center (WOUDC)

4. Reliability of total ozone measurements at WOUDC ?

5. Other topics: GCOS, capacity building

New challenge:

6. IGACO (Integrated Global Atmospheric Chemistry Observations)

7. Next priorities

Terms of references of SAGs

(a) To provide guidance and advice on assessments relevant to OPAC‐EPAC

(b) To develop scientific priorities based on user requirements

(c) To contribute to the GAW Strategic Plan, taking into account the IGACO strategy and regional needs

(d) To implement recommendations, tasks and projects as defined in the GAW strategic plan

(e) To monitor operations at sites and recommend the development of networks, observation technologies and techniques

(f) To develop measurements procedures and guidelines, data quality objectives, and, when applicable, standard operation procedures

(g) To report to the JSSC OPAC‐EPAC on progress on critical problems

(h) To interact with the OPAC for the World Weather Research Programme

Scientific Advisory Group

Group with members:

Frank Baier, Jack Fishman, Sophie Godin‐ Beekmann, Robert Evans, Ulf Koehler, Takashi Koide, Ed Hare, Tom McElroy, Alberto Redondas, Herman Smit, Rene Stübi, Johannes Staehelin, Richard Stolarski, Ronald van der A, Karel Vanicek, Mark Weber

Ex officio members: Geir Braathen (WMO) Johanna Tamminen (IGACO‐O 3 /UV)

Scientific Advisory Group Core business:

Advise and Data Quality control Beginning of 1970s: Discussion on anthropogenic ozone depletion: 1970s: Global Ozone Observing system of WMO

Total Ozone Series of Arosa (performed since 1998 byMeteoSwiss)

1. Column (total) Ozone 1.1. Dobson spectrophotometers: Column

ozone and Umkehr, manual operation

Old instrument (basic design 1930ties). Central Calibration Laboratory/World Calibration Centre (NOAA ESRL, Boulder, Co, USA, Robert Evans): World Primary Dobson instrument: Regularly calibrated by Langley plot method at Mauna Loa Observatory

Global Dobson Calibration System

Regional Standard RA VI D064 (D074)

MOHp, Hohenpbg. Germany

Regional Standard RA V D105

Melbourne Australia

Regional Standard RA II D116

Tsukuba Japan

Regional Standard RA I In preparation SAWS, Pretoria South Africa

Regional Standard RA III In preparation Buenos Aires Argentine

Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn Dobson nnn

Operational Dobsons Global Network approx. 100

Secondary Standard D065

NOAA, Boulder USA

Primary Standard D083

NOAA, Boulder USA

JMA (Japan Meteorol. Agency), (Takashi Koide) In prep.: SAWS South African Weather Service, Pretroria, South Afr. OCBA Observatorio Central Buenos Aires, Argentina SAWS, SOO­HK)

MOHp (Meteorolog.Observatorium Hohenpeissenberg (Ge) (Ulf Köhler) and SOO­HK Solar and Ozone Observatory, Hradec Kralove (Czech Rep.) (Karel Vanicek) BoM (Buro of Meteorology, Australia)

((Russian) Filter Instruments: MGO (A.I. Voeikov Main Geophys. Observatory, St. Petersburg))

Since middle of 1970s: Regular Dobson intercomparisons under the umbrella of WMO (from Ulf

Köhler)

1.2 Brewer Spectrophotometers Column ozone, Umkehr, UV(B), column SO 2, fully automated

Instrument available since 1980s. Central Calibration Laboratory/World Calibration Center, Env. Canada, Tom McElroy: Triad instruments (Toronto), calibrated by Langley plot method at Mauna Loa Observatory (Hawaii, Canada) Biennial Brewer Workshop; calibration: (mostly) private comp.

European Calibration Center, Izana Observatory, Tenerife, Spain (Alberto Redondas) (First) SOPs available In prep: SOPs for intercomparisons Improvements possible

Ozone profile measurements

• From Dobson and Brewer instruments: Umkehr measurements (Sophie Godin‐Beekmann) (see e.g. K. Miyagawa et al., Reevaluation of long term Umkehr data and ozone profiles at Japanese stations, J. Geophys. Res., 114, D07108, doi:10.1029/2008JD010658, 2009).

2. Ozone balloon measurements (Ozone sondes)

QA/SAC, Central Calibration Laboratory, World Calibration Centre: Forschungszentrum Jülich (GE): Herman Smit

Ozone Sonde Intercomparsion Experiment (JOSIE): Chamber in Jülich (Smit et al., 2007)

Ozone Ascent Simulations

Ozone sonde measurements

• Different types of sensors: BM (Brewer Mast (oldest)), many sides moved to ECC (Electrochemical Concentration Cell), KC96, etc.

• ECC: ‐ Different sensor types (SPC‐4A,‐5A,‐6A, ENSCI‐Z)

‐ Different sensing solutions: SST1.0=1%KI+full buffer, SST0.5=0.5%KI+half buffer, or any other SST

• JOSIE: Facility operated as part of GAW/Ozone

Results JOSIE Confirmed by BESOS (Balloon Experiment on Standards for Ozone Sondes) large gondola with many sondes,

flown from Wyoming (USA)) and dual flights

Assessment of Standard Operating Procedures for Ozone Sondes (ASOPOS).

• ECC SOPs adopted in SAG‐ozone meeting 2007

• ASOPOS report: almost in press

Science: Ozone sonde expert meeting (Herman Smit, René Stübi), Jülich (incl. networks NDACC, SHADOZ)

2.Feb.2009, Theme 1: Outstanding issues ‐ What is our real (scientific) understanding of electrochemical O 3 ‐sondes? • Conversion efficiency: ‐ Absorption of O 3 (gas) into sensing solution (liquid) ??

– Chemical kinetics of O 3 +KI (Stoichiometry) ?? • Response time: Impact on vertical O 3 S‐profile and how to correct??

• Background current: Origin and How to correct??

• Pumpflow efficiency: Origin and How to determine??

• Pump temperature: Impact on vertical O 3 S‐profile??

• Box temperature: Impact on O 3 S‐performance??

• Total ozone normalization: Determination and Use as correction factor??

3.Feb.2009: Homogenization of sounding records ‐ How to homogenize sounding records in space and time?? • Inhomogenities/discontinuities exist in sounding records through : Different sensing techniques (e.g. ECC,

BM , KC96, ….)

• Different sensor types (e.g. ECC: SPC‐4A,‐5A,‐6A , and ENSCI‐Z); Different sensing solutions types (SST1.0=1%KI+full buffer, SST0.5=0.5%KI+half buffer, or any other SST); different radiosondes (P,T,Z)

• Sounding records can be homogenized in space (between different stations) or in time (long term changes) through e.g. empirical transfer functions from (i) intercomparison experiments (e.g.JOSIE or BESOS); (ii) dual balloon soundings (iii) other

• How reliable are empirical transfer functions ? What methodology for homogenization ?

4.Feb.2009: Recommendations & action plans

3. World Ozone and Ultraviolet Data Center (World Data Center, Env. Canada, Ed Hare)

(World Data Centre for Remote Sensing of the Atmosphere (WDC‐RSAT), Frank Baier (DLR)) ?

Use of data (clients)

• Trend analysis studies (scientific studies, WMO/UNEP Assessments)

• Satellite validation • Validation of numerical models (stratospheric/global tropopspheric ozone cycle)

How reliable are measurements ?

• Concept (in preparation): Data Quality Indicators • Ozone sondes: Problem of different ECC‐sonde data

4. Reliability of total ozone measurements at WOUDC ?

V.E. Fioletov, G. Labow, R. Evans, E.W. Hare, U. Köhler, C.T. McElroy, K. Miyagawa, A. Redondas, V. Savastiouk, A.M. Shalamayanshi, J. Staehelin, K. Vanicek, and M. Weber:

Performance of ground‐based total ozone network assessed using satellite data, J. Geophys. Res., 113, D14313, doi:10.1029/2008JD009809 (2008)

(Pre‐ozone SAG meeting in Tenerife)

Satellite measurements: ‐ 1978‐1985 (Nimbus 7 TOMS (Version 8);

‐ 1986‐1990 (Nimbus 7 TOMS (Version 8); 1991‐1995: Nimbus 7 TOMS (Version 8), Meteor 3 TOMS (Version 8), GOME (Univ. Bremen vers.);

‐ 1996‐2000: EP TOMS (Version 8), GOME (Univ. Bremen vers.)

‐ 2001‐2006: EP TOMS (Version 8), GOME, OMI (NASA version)

Criteria of comparison (60 o S‐60 o N): suspect; outlier (in brackets: ZS Observ.)

1. Mean difference (%): ±3 (±4); ±4 (±5);

2. Standard deviation of daily difference (%): 4.5 (6); 6 (7)

3. Standard deviation of monthly difference (%): 3 (4) ; 4 (5)

4. Seasonal amplitude of the difference (%): 2 (2.6); 3 (3.2)

5. Range of annual mean difference (%): 4 (4); 5 (5)

Results: Many stations with (serious) problems

0

20

40

60

80

100

1978­1985 1986­1990 1991­1995 1996­2000 2001­2006

0

10

20

30

40

50

60

1978­1985 1986­1990 1991­1995 1996­2000 2001­2006

Dobson Brewer Filter

Number o

f stations

Relative

number of stations in % Top: Relative number

of sites (in percent) with “no issues” in the record in 5 bins for Dobson, Brewer, and Filter instrument (60°S and 60°N) Bottom: Number of sites with measurements at WOUDC

5. Other topics

• Capacity building: reuse/refurbishment of unused Dobson instruments (funding question), training (Karel Vanicek, Robert Evans, Ulf Köhler)

• Near Real Time Delivery (Geir Braathen)

Other achievement:

Inclusion of (GAW)‐ozone measurements (total ozone and ozone sondes) in GCOS (Global Climate Observing System)

6. IGACO (Integrated Global Atmospheric Chemistry Observations)

Chemical species/parameters Air Quality Oxidation Capacity Climate Stratospheric Ozone

Depletion

Note

O 3 ü ü ü ü

H 2 O (water vapour) ü ü ü ü Stratosphere

CO ü ü ü CO 2 ü CH 4 ü ü ü Stratosphere HCHO ü ü VOCs ü ü N 2 O ü ü Stratosphere NO x = NO+NO 2 HNO 3

ü ü

ü ü

ü ü ü

Stratosphere

SO 2 ü ü ü ü BrO, ClO, OClO HCl, ClONO 2 CH 3 Br, CF 3 Br, CFC­11, CFC­12, HCFC­22

X x

ü ü ü ü

Stratosphere

aerosol optical properties ü ü ü Needed for UV

Spectral actinic flux ü ü

IGACO: An Integrated Global Atmospheric Chemistry Observations Theme for the IGOS Partnership, IGOS Atmospheric Chemistry Theme Report (ESA­SP1282 / WMO GAW Report No. 159), 2004.

Implementation IGACO:

IGACO‐Ozone and UV Radiation Implementation Plan Anssi Mälkki (replaced by Johanna Tamminen) FMI, Geir Braathen, Johannes Staehelin, Anne Webb

GAW report 182 (in press), 2009

4 activity clusters

‐ Cluster A: Stratospheric Ozone

‐ Cluster B: Upper tropospheric/lower stratospheric ozone

‐ Cluster C: UV radiation

‐ Cluster D: Services • New activity of cluster A (A9): IO 3 C/WMO‐GAW Expert Team

on Absorption Cross Sections of Ozone (ACSO): starting work next week

7. Next priorities

• Further integration of IGACO‐O3/UV (satellite experts: Jack Fishman, Richard Stolarski, Ronald van der A, Mark Weber)

• SOPs Brewer intercomparisons

• WOUDC: Data Quality Indicators

• Workshop comparison DOAS/SAOZ measurements with satellite measurements (Vitali Fiolettov)

• Data Re‐evaluation workshop (Karel Vanicek)

• Harmonize ozone sonde measurements (transfer functions)

• Retrieval Umkehr measurements

Acknowledgment

Geir Braathen (WMO)

Johanna Tamminen (IGACO‐O 3 /UV)

Frank Baier, Jack Fishman, Sophie Godin‐ Beekmann, Robert Evans, Ulf Koehler, Takeshi Koide, Ed Hare, Tom McElroy, Alberto Redondas, Herman Smit, Rene Stübi, Johannes Staehelin, Richard Stolarski, Ronald van der A, Karel Vanicek, Mark Weber

(personal) Announcement

Symposium on Atmospheric Chemistry and Physics at Mountain Sites

• Tentative dates: 8‐10 June 2010, probable location: Switzerland, Berner Oberland

• Organizing Committee: Urs Baltensperger (PSI); Brigitte Buchmann (Empa); Erwin Flückiger (High Altitude Research Stations Jungfraujoch and Gornergrat); Dominique Ruffieux (MeteoSwiss);

Johannes Staehelin (IACETH)