Contrail radiative forcing over the Northern Hemisphere from 2006 Aqua MODIS...
Radiative forcing due to linear-shaped jet contrails is calculated over the Northern Hemisphere for four seasonal months using 2006 Aqua Moderate-resolution Imaging Spectroradiometer cloud and contrail property retrieval data in a radiative transfer model. The 4 month mean shortwave, longwave, and net radiative forcings normalized to 100% contrail cover are 5.7, 14.2, and 8.5 Wm2. Mean total net forcing over the northern half of the globe varies from 9.1 mW m2 during October to 12.1 mW m2 in January and is only representative at 01:30 and 13:30 LT in nonpolar regions. In some dense flight traffic corridors, the mean net forcing approaches 80 mW m2. Scaling the 4 month average of 10.6 mW m2 to the Southern Hemisphere air traffic yields global mean net forcing of 5.7 mW m2, which is smaller than most model estimates. Nighttime net forcing is 3.6 times greater than during daytime, when net forcing is greatest over low clouds. Effects from contrail cirrus clouds that evolve from linear contrails are not considered in these results.