Ozone soundings serve to integrate models, aircraft and ground-based measurements for better interpretation of atmospheric losses (stratosphere) and pollution (troposphere). A well-designed network of ozonesonde stations answers questions that cannot be solved by short campaigns or current satellite technology. The Match campaign (Rex et al. 1998) was designed specifically to follow ozone depletion within the polar vortex; the standard sites are at middle to high northern hemisphere latitudes. Short-term strategic networks operated over North America in July-August 2004 within the ICARTT/INTEX-A/NEAQS (International Consortium on Atmospheric Research on Transport and Transformation/Intercontinental Chemical Transport Experiment/New England Air Quality Study) and during the 2006 INTEX-B (INTEX Ozonesonde Network Study (http://croc.gsfc.nasa.gov/intexb/ions06.html) and TEXAQS/GOMACCS (Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study). A global network designed to address questions about ozone in the equatorial zone, SHADOZ (Southern Hemisphere Additional Ozonesondes; http://croc.gsfc.nasa.gov/ shadoz), has operated since 1998 in partnership with NOAA, NASA and the Meteorological Services of host countries (Thompson et al. 2003a, b). Examples of findings from these networks are described.