Case studies of aircraft contrails using the 1.375-micron channel and IR emission channels on MODIS

The emissions from subsonic jet aircraft flying near the upper tropopause can lead to the formation of condensation trails (contrails). When the relative humidity near the upper troposphere is high, contrails can persist for a long time and embed in ordinary cirrus clouds. In recent years there has been interests in assessing the radiative effects of contrails on the Earth´s radiation budget. Imaging data collected with NOAA AVHRR and GOES types of satellite instruments infrequently show aircraft contrails. The 36-channel MODIS instrument on the Terra Spacecraft has improved radiometric sensitivities and spatial resolution. It makes the task of contrail detection much easier, particularly with the 1.375-micron cirrus-detecting channel. The authors present examples of contrail observations from MODIS data