The Network for the Detection of Atmospheric Composition Change (NDACC), formely known as the Network for the Detection of Stratospheric Change (NDSC), is a set of high quality, remote-sounding research stations for observing and understanding the physical and chemical state of the stratosphere. These stations, where ozone and key ozone-related parameters are measured, are complemented by both secondary stations and satellite measurements. Following five years of planning, instrument design and implementation, the NDACC began network operations in January 1991.

The principal goals of the network are:

* To study the temporal and spatial variability of atmospheric composition and structure in order to provide early detection and subsequent long-term monitoring of changes in the physical and chemical state of the stratosphere and upper troposphere; in particular to provide the means to discern and understand the causes of such changes.

* To establish the links between changes in stratospheric ozone, UV radiation at the ground, tropospheric chemistry, and climate.

* To provide independent calibrations and validations of space-based sensors of the atmosphere and to make complementary measurements.

* To support field campaigns focusing on specific processes occurring at various latitudes and seasons.

* To produce verified data sets for testing and improving multidimensional models of both the stratosphere and the troposphere.

The dataset contains high quality measurements of a wide range of stratospheric chemical species and parameters derived from instruments operated at a number of ground stations around the world.