Stratospheric influence on upper tropospheric tropical cirrus

Radiosonde data from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program Nauru99 experiment revealed waves with downward phase propagation from the lower stratosphere into the upper troposphere. The occurrence of cirrus clouds and the tropical tropopause structure were closely related to these waves. This study reveals a close relationship between upper tropospheric cirrus and large-scale dynamics, suggesting that tropical cirrus cannot be studied in isolation from planetary scale forcing.