VINTERSOL (Validation of INTERnational Satellites and study of Ozone Loss and also "Winter sun" in the Scandinavian languages ) was a major European field campaign studying stratospheric ozone.

It took place from late 2002 until mid 2004 as a continuation of previous campaigns like EASOE (1991/92), SESAME (1994/95) and THESEO (1998/2000).

It involved ground based measurements as well flights of scientific planes like the Russian M-55 "Geophysica" and several stratospheric balloon flights divided in three main phases: intensive Arctic ozone loss studies in the 2002/03 winter/spring, ozone loss studies in the Antarctic winter and spring 2003, balloon and aircraft studies in the tropics in early 2004.

For the Arctic phase three stratospheric balloons were launched from the Swedish base of ESRANGE near Kiruna in December 2002.

The antarctic phase included the launch of near 600 ozonesondes from several bases in the white continent, also supplemented by satellite studies and ground-based measurements. It was the most comprehensive analysis of ozone loss rates in the Antarctic ozone hole since his discovery in middle 80's.

The final phase took place between January and March of 2004 and involved aircraft measurements under a program denominated TROCCIBRAS and several balloon flights performed from Bauru, Sao Paulo, Brazil. This late effort was denominated HIBISCUS campaign (click in the entry below for more details).