Feb. 26, 2026, 8:37 a.m.

Project: STEP

The Atmospheric Science Data Center (ASDC) has released data for the Stratosphere-Troposphere Exchange Project (STEP). STEP had two mission objectives: Investigate mechanisms and rates of irreversible transfer of mass, trace gases, and aerosols from troposphere to stratosphere and in the lower stratosphere; and explain the observed dryness of the stratosphere. Two deployments took place with U-2 flights in April to May 1984, while the ER-2 flights were conducted from January to February 1987 in and around Darwin, Australia. While data is available for the NASA ER-2, there is no data archived for the NASA U-2, however, it was noted that the U-2 measured horizontal wind, temperature, pressure, water vapor, ozone, and cloud condensation nuclei (CCN).

Data Access:

STEP Landing Page
Earthdata Search
Direct Data Download