GRUAN participated in the 2010 CIMO intercomparison campaign in China, represented by Holger Vömel as part of the organizing committee, Franz Immler from the lead centre as well as Junhong Wang and Masatomo Fujiwara of the working group as technical experts.

The CIMO inter-comparison campaign included payloads carrying scientific sounding instruments (SSI) in addition to those carrying approved routine operational radiosondes. The SSI payload included instruments that provided observations of atmospheric parameters in altitude regions where routine operational sensors show their limitations. The multi thermistor temperature sensor provided by Lockheed Martin Sippican and the fast response time sensor from Meisei provided reference temperature measurements. Both are candidate instruments for GRUAN. The Lead Center provided 10 Cryogenic Frostpoint Hygrometer (CFH) sondes and Hokkaido University provided 3 CFH sondes. These instruments were operated by the Lead Center and provided humidity reference data for both, troposphere and stratosphere. Vaisala tested its DryCap humidity sensor that is intended to measure water vapor in the stratosphere using the polymer technique. Overall, 12 SSI flights were launched at the CIMO intercomparison campaign at Yangjiang.

The Lead centre will contribute to the CIMO report on the Yangjiang campaign in particular regarding the SSI data. A first draft report is scheduled to be ready in November 2010 and the final report is due April 2011. According to the CIMO data policy no results from the inter-comparison can be published before the official report has appeared in print.

Reports

WMO/TD-No. 1580: Instruments and Observing Methods Report No. 107; J. Nash, T. Oakley, H. Vömel, LI Wei; WMO Intercomparison of High Quality Radiosonde Systems, Yangjiang/China, 12 July - 03 August 2010.