The Stratosphere-Troposphere Exchange Project (STEP) Data

This mission was the last of 6 STEP missions which started with the Variability and Global Tropospheric Experiment (GTE) Coop assignment in April 1984, based in Moffett Field, California. Altogether, 4 science missions and 2 intercalibration missions comprised STEP, with the science missions 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 also observed the extreme dryness of the stratosphere. STEP was carried out under NASA and the National Oceanic Atmospheric Administration (NOAA). 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.