1. Expert team on Upper Air System Intercomparisons,
Agenda 5.1
Comparison of Snow White and RS90 measurements from WMO GPS Radiosonde Test, Alcantara , Brazil Richard Smout,Darren Lyth, John Elms John Nash Met Office, Exeter, Devon, UK

2. Inside a Snow White used in Brazil

3. Comparison of daytime measurements

4. Comparison of daytime measurements

5. Dewpoint comparison

6. Sample of temperature and relative humidity data
from WMO GPS Radiosonde Comparison

7. Snow white overheating
after entering thin cloud at minute 60

12. Conclusions
Both Snow White and the Vaisala RS90 suffered problems during the Brazilian test.
Hence, more reliable systems need to be deployed in future tests.
Neither system should be considered an absolute reference, but both fall into the category of higher quality radiosonde relative humidity measurements