How to avoid contrail cirrus

Abstract

The impact of air traffic on climate is dominated by the contribution of aircraft induced cirrus. Hence, any mitigation strategy has to consider the production of contrails and cirrus clouds. Here we use operational radiosonde data with high vertical resolution to estimate the effect of a small change in flight altitudes to avoid flight in ice supersaturated air, hence to suppress contrail and cirrus formation. It is shown that a substantial fraction of contrails and contrail induced cirrus can be avoided by relatively small changes in flight level, due to the shallowness of ice-supersaturation layers.