ASOPOS
Assessment of Operating Procedures for Ozone Sondes
Table of Contents
In 2001 under the auspices of WMO/GAW, ASOPOS (Assessment of Standard Operating Procedures for Oone Sondes) was initiated with the intent of defining easy to follow operating procedures that can be consistently implemented and will provide data of high quality that are comparable between ozone sounding stations.
The assessment started with the WMO meeting of ozone sonde experts held in Geneva at 1-3 May 2001 to critically examine the JOSIE 2000 (conducted in September 2000 at the World Calibration Center for Ozone Sondes at Juelich, Germany) and to evaluate the entire JOSIE series of experiments. At this meeting provisional -SOP's (Standard Operating Procedures) were unamously agreed by the panel of ozone sonde experts.
In April 2004 the Balloon Experiment on Standards for Ozone Sondes (BESOS) field campaign at the University of Wyoming at Laramie, USA, was conducted to test the provisional SOP's for ECC-ozonesondes under field conditions.
In a next step a second WMO meeting of ozone sonde experts will be held at Jülich, Germany to evaluate the BESOS-results and to continue ASOPOS to evaluate JOSIE- and BESOS-results in combination with other laboratory and field studies in order finally to establish WMO-recommended SOP's, for the different major types of ozone sondes used in the GAW-ozone sounding.
Introduction
Ozone trend assessments have shown that there is an urgent need to improve the homogeneity and quality of ozone sounding data to ensure confidence in observed trends [WMO Scientific Assessment of Ozone Depletion, 1995, 1999, 2003]. To achieve this goal, standardisation of the preparation procedures and data correcting methods in the near future is essential. But also important is to obtain a better and more detailed documentation of the procedures and methods applied in the past at the different long term ozone sounding stations [SPARC/IOC/GAW-Assessment of trends in the vertical distribution of ozone, 1998]. It is of critical importance to establish SOPs, particularly with regard to ECC-ozone sondes [Smit and Kley, 1998]. JOSIE experiments have shown that the characteristics of the two ECC-sonde types is not always the same, even not when operated under the same conditions and can have significant differences (Smit and Straeter, 2004-a,b). The goal of WMO/GAW is to establish SOPs for each of the three major types of ozone sondes (ECC, BM+hybrids and KC79/96) used in the global ozone sounding network.
Under the auspices of WMO/GAW, we initiated in 2001 ASOPOS (Assessment of Standard Operating Procedures for Oone Sondes) with the WMO meeting of ozone sonde experts held in Geneva at 1-3 May 2001 to critically examine the JOSIE 2000 (conducted in September 2000 at the World Calibration Center for Ozone Sondes at Juelich, Germany) and to evaluate the entire JOSIE series of experiments. At this meeting provisional -SOP's (Standard Operating Procedures) were unamously agreed by the panel of ozone sonde experts. Further, it was decided that the preliminary SOPs recommended by JOSIE had to be tested through an intercomparison in the real atmosphere for quality assurance and suitability before the procedures are applied to sonde launched at various GAW stations. Therefore in April 2004 the Balloon Experiment on Standards for Ozone Sondes (BESOS) field campaign at the University of Wyoming at Laramie, USA, had been conducted to test the provisional SOP's for ECC-ozonesondes.
In a next step we will held a second WMO meeting of ozone sonde experts held at Jülich, Germany to evaluate the BESOS-results and to continue ASOPOS to evaluate JOSIE- and BESOS-results in combination with other laboratory and field studies in order finally to establish WMO-recommended SOP's, for the different major types of ozone sondes used in the GAW-ozone sounding network.
References
Smit, H.G.J., and D. Kley, Jülich Ozone Sonde Intercomparison Experiment (JOSIE), WMO Global Atmosphere Watch report series, No. 130 (Technical Document No. 926), World Meteorological Organization, Geneva, 1998.
Smit, H.G.J., and W. Straeter, JOSIE-1998, Performance of ECC Ozone Sondes of SPC-6A and ENSCI-Z Type, WMO Global Atmosphere Watch report series, No. 157 (Technical Document No. 1218), World Meteorological Organization, Geneva, 2004-a
Smit, H.G.J., and W. Straeter, JOSIE 2000: The 2000 WMO international intercomparison of operating procedures for ECC-ozone sondes at the environmental simulation facility at Jülich, WMO Global Atmosphere Watch report series, No. XXX (Technical Document No. YYYY), World Meteorological Organization, Geneva, 2004-b
SPARC-IOC-GAW Assessment of Trends in the Vertical Distribution of Ozone, SPARC report No.1, WMO Global Ozone Research and Monitoring Project Report No. 43, 1998.
WMO (=World Meteorological Organization) , Scientific Assessment of Ozone Depletion: 1994, Global Ozone Research and Monitoring Project - Report No. 37, World Meteorological Organization, Geneva, 1995.
WMO (=World Meteorological Organization) , Scientific Assessment of Ozone Depletion: 1998, Global Ozone Research and Monitoring Project - Report No. 44, World Meteorological Organization, Geneva, 1999.
WMO (=World Meteorological Organization) , Scientific Assessment of Ozone Depletion: 2002, Global Ozone Research and Monitoring Project - Report No. 47, World Meteorological Organization, Geneva, 2003.
Proposed strategy
Major tasks of the assessment will be: (i) to identify and evaluate major existing operating procedures and their impact on sonde data quality and (ii) establish SOPs for each of the 3 major sonde types. Further strategy or design of the assessment could be as follows:
- Field testing and validation of preliminary SOPs. during BESOS in April 2004
- BESOS/ASOPOS: Second WMO-meeting of ozone sonde experts: (i) evaluation and formulation of standard operating procedures (ii) strategy and action plan to establish SOP's as WMO/GAW-document and (iii) future strategy to establish QA for ozone sondes as an essential and routineous part of GAW ozone sounding network.
- Preparation of draft ASOPOS-report by assessment panel to include final SOP document to distribute among broad community of ozone sonde users to review
- Preparation of final ASOPOS-report by assessment panel including final SOP document
- The SOP for each major sonde type is published as a GAW Report to give all details of the WMO recommended procedures to prepare and operate ozone sondes in the global ozone network and recommended data reduction procedures.
