An algorithm to derive the amount of linear contrails from satellite data was developed at Institut für Physik der Atmosphäre at Oberpfaffenhofen. This method is used here to derive contrail statistics over Europe and Southeast- and East Asia. They are used at NASA for the continental USA.
Investigations on the details of contrail development have been performed by in-situ measurements and numerical models of the microscopic cloud physics. To estimate the global effect of contrails we use a climate model.
Aging contrails often cannot be discriminated from natural cirrus clouds and the combustion products of the air traffic might lead to changes in the cirrus formation process. Research is going on to determine the amount and effect of this additional cloudiness.