This data was collected from the Stratosphere-Troposphere Exchange Project (STEP) conducted onboard the NASA ER-2 aircraft in January and February, 1987 based in Darwin, Australia. This mission was the last of 6 STEP missions which began with the Global Tropospheric Experiment (GTE) in April 1984.

The Darwin, Australia phase of STEP utilized 15 instruments and accessed the world's highest, coldest tropopause as well as the largest penetrating cumulonimbus anvils. The flights were designed to test a dehydration mechanism proposed by Danielsen (1982), as well as to acquire sufficient data to test and develop other hypotheses.

The STEP missions were designed to investigate different aspects of stratosphere-troposphere exchange (in mass, trace gases, and aerosols), including cloud-free and cloud-dominated mechanisms in both the mid-latitudes and the tropics. STEP was carried out under NASA and the National Oceanic Atmospheric Administration (NOAA).

Data from the NASA/NOAA aircraft campaign based in Darwin, Australia in January and February 1987. Designed to investigate mechanisms of equatorial stratosphere-troposphere exchange. Measurements include trace gases and aerosol in cloud free and cloud dominated conditions. This dataset is public.