CIMO Expert Team on Upper-Air Systems Intercomparisons, 2nd Session; & International Organizing Committee (IOC) on Upper-Air Systems Intercomparisons, 2nd Session
28-30 November 2005, in Geneva (Switzerland)

Attendees
Dr John Nash - ET Chairman, Vice Chairman of CIMO, Met Office UK
Dr Beenay Pathack - Project Manager of the Intercomparison, Meteorological Services Mauritius
Dr Miroslav Ondras - CIMO Secretary
Mr Yatian Guo - China Meteorological Administration
Mr Yvan Lemaitre - Météo France
Mr Henk Klien Baltink - Royal Netherlands Meteorological Institute
Mr Carl A. Bower - Observing Services Division, NOAA, USA
Mr Richard Smout - Met Office UK
Dr Bernard Calipini - Météo Swiss
Mr Francis Schmidin - NASA Ozone Project Manager, USA
Mr Rainer Dombrowsky - NOAA liaison Dept. Homeland Security, USA
Mr Sergey Kurnosenko - Software consultant to the Mauritius Intercomparison
Prof Hans Richner - IAC ETH, ETH Zentrum CH, Switzerland
Mr Tom Curran - Lockheed Martin Sippican
Mr Florian Schmidmer - Graw
Mr Paul Ruppert - Meteolabor
Mr Fred Clowney - InterMet
Mr Rémy Pepin - Modem
Mr Shinichi Tsuda - Meisei
Mr Makoto Fujita - Meisei
Mr Hannu Jauhianinen - Vaisala Oyj
Ms Christine Charstone - HMEI Administrator
Mr Bruce Sumner - HMEI Executive Secretary

Item 1.1 - Opening of the session by WMO Deputy Secretary General, Prof Hong Yan
Prof Hong Yan gave a very positive introduction to the session. He noted the success of the Mauritius Intercomparison and acknowledged the part played by HMEI in the success of this event. He congratulated the participating manufacturers, in their quality of their radiosondes and the their success in meeting
WMO standards.

Item 6.1 - Interoperable Upper-Air Systems
Fred Clowney from InterMet presented a description of the InterMet RDF Interoperable system; advantages of this type of systems were outlined. Problems and issues related to compatibility were also addressed. Please go to this link to see this PowerPoint Presentation.

There was a discussion on the difficulties of interoperability, the situations that can arise when for any reason a change in radiosondes is adopted by a user with an interoperable system and the financial considerations.

Action:
HMEI Manufacturers were asked to compile a discussion document for the first step towards a basis for an eventual paper for CIMO in December 2006, on the issues to be considered when new upper-air equipment and systems need to be put in place, including the consideration of an interoperable type system. The manufacturers discussion document to be given to CIMO secretariat by February/March 2006, for consideration by CBS and CIMO.

Fred Clowney from InterMet will draft the document on behalf of the HMEI attendees and this will be passed to the other HMEI attendees for final refinement to be done during the period of AMS, Jan/Feb 2006 in Atlanta. The final draft will then be passed to the CIMO Secretariat by March 2006.

Item 6.2 - Global Criteria for Tracing the Improvements of Radiosondes over the Last Two Decades
This paper by Pierre Jeannet, Carl Bower and Bernard Calipini, was presented by Bernard Calipini. 

Item 6.3 - Recent Comparison Results between the NASA ATM Radiosonde, Modem, InterMet and Sippican Radiosondes
Presented by F. J. Schmidin from NASA. This paper argued the advantages in accuracy of using multiple thermistors on radiosondes, as do ATM radiosondes that use five thermistors.

Item 2 - Report of the Chairman
The ET Chairman Dr John Nash briefed the meeting on the activities since the First Session of this ET in March 2004. In particular this was the WMO Intercomparison of High Quality Radiosonde Systems in Mauritius, February 2005.

Item 3 - Draft Final Report of the WMO Intercomparison of High Quality Radiosonde Systems
The discussion and revising as appropriate of the report had the aim of creating a final version of the report that would satisfy all the meeting attendees.

In the discussion manufacturers and HMEI strove to ensure that the report was presented in the clearest possible way, in order to understand accurately and in an unbiased way the results and relative measurements shown in the graphs and wording of the report.

The sessions on Item 3 were spread over all three days of the session, written corrections were to be passed to Dr Nash and on the final day of the session the final draft was checked.

The Draft Final report of the Intercomparison will be available at: TBA (expected February 2006)

Presentation - WMO Intercomparison of High Quality Radiosonde Systems in Mauritius, Supporting Remote Sensing Systems February 2005
Prof Hans Richner presented this, he was in Mauritius in charge of this supporting activity with Remote Sensing Systems.
The systems used were:
CHAMP satellite (radio occultation with GPS); GPS water vapour; cloud water; ceilometer.
For more information on this please contact Prof. Richner via: www.iac.ethz.ch/staff/richner

Item 4 - Future Intercomparisons
The ET/IOC suggested that WMO Regional Intercomparisons take place in the next 2-4 years to link the High Quality radiosondes, as seen in the Mauritius 2005 Intercomparison, with other radiosondes used in certain regions.

Presentation - Some Progress in Upper-Air Observation Network Construction in China
Mr Yatian Guo from the China Meteorological Administration gave the presentation, which indicated the current status of the Chinese network of radiosondes, and showed some data on the performance of their systems.

The China Meteorological Administration is currently upgrading to using Nanjing Daqiao Machine Factory Ground Stations, with Shanghai No. 23 Radio Factory manufactured GTS1 Radiosondes.

The presentation noted that China would like to participate in a future High Quality Radiosonde Intercomparison. The presentation proposed a WMO/CIMO Intercomparison, in perhaps Beijing in Autumn 2006; the comparison would be with the Chinese system (L-band radar and electronic radiosonde system, GPS radiosonde) and other manufacturers' High Quality Radiosonde Systems (such as Vaisala, Meisei, etc.). A preliminary plan was made for such an Intercomparison in 2007.

Item 5 - Work Plan
Mr Rainer Dombrowsky chaired the discussion on the work plan points. The ultimate aim of the work plan is to have all the work for Intercomparisons ready for presentation at CIMO-XIV in December 2006.

The discussion centred around the progress the various people responsible for tasks had made towards their deadlines and ensuring that deadlines for tasks in the work plan had been or would be met in sufficient time before CIMO-XIV. 
See the agreed work plan a in the pdf CIMO report of the meeting at:  http://www.wmo.ch/web/www/IMOP/reports.html

Item 7 - Draft Report of the Session
Mr Dombrowsky asked for comments on the draft of the report of the session and requested written corrections to be passed to Dr Ondras so that they could be incorporated into the final report.

The CIMO Report of the Session is available  as a pdf file at: http://www.wmo.ch/web/www/IMOP/reports.html

Meeting Closed at 3.30pm on 30th November 2005