Contrail coverage over the USA from NOAA and EOS Satellite Data

Contrails, like natural cirrus clouds, can cause a warming of the Earth-atmospheric system through by acting like a greenhouse gas and can produce some cooling of the surface by reflecting sunlight. To better assess the climatic impact of contrails, it is essential to determine the variability of the contrail microphysical properties, their impact on the atmospheric radiation budget, and their relationship to the atmospheric state. To determine the variability of contrail properties, this paper continues the analyses of Advanced Very High Resolution Radiometer (AVHRR) data from the NOAA-15, 16, and 17 satellites Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellites. These satellites provide a relatively comprehensive coverage of the daily cycle of air traffic. The 1-km data are analyzed with an automated algorithm to produce contrail areal coverage, optical depth, effecvtive ice crystal size, and shortwave and longwave radiative forcing over the continental United States of America. The results are used to characterize the diurnal, seasonal, and interannual variations of contrails and their properties over the USA between 2001 and 2003. They are compared to upper tropospheric humidity data from the National Centers for Environmental Prediction (NCEP) to help determine their dependence on the atmospheric state. The results will be valuable for developing models of contrail effects and methods for mitigating the impact of aviation on climate.