Estimation of Contrail Frequency and Radiative Effects over the Taiwan Area
Journal
Terrestrial, Atmospheric and Oceanic Sciences
Journal Volume
12
Journal Issue
1
Pages
155-178
Date Issued
2001
Author(s)
Abstract
The radiative effect of aircraft contrails over the Taiwan area was stud ied using a climatological analysis of contrail occurrence fr equency and numerical simulations of contrail formation. Although the most suitable altitude for the formation of contrails is 14-16 km, most contrails appear at heights between 10 and 12 km due to the altitude constraint on flying. Win ter and spring are the most favorable seasons for contrail formation, whereas summer is the most unfavorable. After formation, 86% of the contrails will dissipate while the remainder will grow and persist. For more detailed analysis, we classify contrails into 12 types according to the climatology of contrail-forming conditions. The microphysical and radiative properties of each type of contrails were simulated using a two-dimensional cirrus model. From the simulation we obtained a time-averaged top-of-atmosphere longwave radiative forcing of about 1.1 W m2 and 16 W m2 directly under a dissipating and persistent contrail, respectively; whereas the shortwave radiative forcing, with the sun directly overhead, were -2.6 W m2 and -40 W m2, respectively.
SDGs
Type
journal article