Determining the cascade of passive scalar variance in the lower stratosphere.

Using aircraft data from 7630 commercial flights, we determine the flux of temperature and ozone variance from large to small scales in the lower stratosphere. The relation that we use for this purpose is a form of the classical Yaglom relation [A. M. Yaglom, Dokl. Akad. Nauk SSSR 69, 743 (1949)] for the third-order scalar-velocity structure function. We find that this function is negative and that it depends linearly on separation distance in the mesoscale range for temperature as well as ozone.