Trace amounts of hydrocarbons can significantly influence the chemistry of the atmosphere. Accurate identification and mixing ratios of the numerous hydrocarbons present are necessary prerequisites for understanding the various species' potential contributions to important atmospheric chemical cycles. The large number, low mixing ratios, and high reactivities of the hydrocarbons present suggest that a carefully controlled intercomparison study is needed.

The National Center for Atmospheric Research (NCAR) announces plans by an international committee of scientists to develop the protocol to be used in intercomparing ambient hydrocarbon samples. The committee welcomes the participation of all scientists who are now or plan to be involved in the analysis of ambient levels of hydrocarbons from rural or clean air.