The Atmospheric Science Data Center (ASDC) has released data for the Stratosphere-Troposphere Exchange Project (STEP).
The STEP Project's mission was to 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).