Airplanes' Condensation Trails
Development of Methods to Research Atmosphere Contaminations, Conditions of Formation and Composition of Airplanes' Condensation Trails
Tech Area / Field
- ENV-APC/Air Pollution and Control/Environment
8 Project completed
Senior Project Manager
Ryzhova T B
Gromov Flight Research Institute, Russia, Moscow reg., Zhukovsky
- AIRBUS SAS, France, Blagnac\nDeutsches Zentrum für Luft- und Raumfahrt e.V. / Institut für Physik der Atmosphare, Germany, Wessling
The goal of the project is carrying-out the fundamental investigations and technical development in the area of environment conservation.
Present-day evaluations of anthropogenic impact on environment confirm the importance of better understanding the role of atmospheric contaminations (particles, aerosols and gases) in direct and indirect influence on climate changing and on ozone chemistry. The influence of these contaminations appear in increasing the atmosphere radiation properties, i.e. "hothouse" effect. Cirrus clouds play a very substantial role in that process, therefore increase of their area, as a result of anthropogenic impacts, may in the future be a cause of noticeable growth of terrestrial surface temperature.
The aviation introduces significant contribution in contamination of the upper troposphere and lower stratosphere. Combustion products, emitted by aircraft engines, rise concentration of the carbon dioxide, water vapour, methane, nitrogen oxides and oth. and contain aerosols and particles which in one's turn initiate the formation and development of the cirrus cloudiness. In this context expected increasing the air traffic volume may influence significantly on the length, congestness (thickness) and frequency of formation of cirrus clouds. The most substantial factor of aviation influence on formation and development of cirrus clouds are condensation trails (contrails), which are created as a result of condensation and freezing of water vapour, contained in the aircraft engine exhaust jet. The condensation trails are created at the same altitudes as the cirrus clouds, and they have a structure similar to them. On the base of IPCC report in 1999 (A Special Report of Working Group I and III of the Intergovernmental Panel on Climate Change, April 1999) (In the process of the Project further development the updated results of the recent research will be taken.into account /see, in particular, the results of the AERONET Thematic Network "Aircraft Emission and Reduction Technologies" Workshop, Working Paper No. 15, Sheffield, 13-14 November, 2003/) by the beginning of 1990s the area, covered by contrails, was estimated on average about 0,1% of terrestrial surface, but it greatly differs on regions, and by 2050 it was proposed its increase up to 0,5%. The expected increase will be owing to both increasing the air traffic volume, and rising the aircraft engine efficiency. But by far more substantial is the fact, that at appropriate meteorological conditions (increased humidity at low temperatures, usually lower than -40°C) in the upper layers of troposphere and lower layers of stratosphere the contrails may serve as launching mechanism ("trigger" effect) to forming and, especially, for intense development of cirrus clouds, existing nearby laying the airway. On the data of abovementioned IPCC Report, late in 1990s cirrus cloudiness increase, as a result of aviation impact, was estimated in the limits of 0,2% of terrestrial surface, and by 2050 it may rise up to 0,8% (i.e. rise in 4 times).
The complex consideration of problems, associated with environmental conservation and with searching the ways for their solution has permitted to come to conclusion about possibility and expediency of aircraft using, and using the special equipment to aviation monitoring the contamination of air medium, including investigations of aircraft engines emissions influence on atmosphere contamination in airports areas and in the cruise flight conditions.
The organization of allocation of optimal routes, with regards to ecological aspects, may be as one of possibilities for decrease of aircraft engines emission impact during the flights in upper troposphere and lower stratosphere.
In this project it is suggested to solve the following scientific and technical tasks:
- development of the experimental investigation method of the contrails formation conditions and their characteristics using flying test beds-probing aircraft and generator aircraft;
- development of the calculation and prediction method of the formation conditions and contrails characteristics taking into account the level of humidity supersaturation when mixing jet and atmosphere;
- fulfillment the experiment and the identification the calculation model having the results of experiments.
In the course of project performing it is supposed to realize:
- development of the method and the experimental means to invest: gate atmosphere pollution, contrails formation conditions and their characteristics and the relation with cirrous cloud parameters;
- development of the method to perform solo and paired flights of aircraft-gas generator and aircraft-prober taking into account the formation conditions prediction of contrails and carrying-out flight experiment;
- development of the method to investigate the contrails formation in areas loaded routes for civil airplanes;
- identification of the calculation model with flight experiment results to estimate the contrails formation conditions and their characteristics and with measuremental results ot the contrails parameters in areas of loaded routes for civil airplanes.
Later on (out of frameworks of this Project) on the base of developed procedures and means it is supposed to carry-out the flight research of atmosphere contaminations, process of contrails formation and their interconnection with cirrus clouds. Using results of such research, the proposals will be developed on creation measures for decreasing influence of airplanes' condensation trails an ecology.
Role of Foreign Collaborator
There is interest in the results of work from firm DLR e.V.-German Aerospace Center Transport Research (Verkehrs-forschung) GERMANY Koeln D-51147 and DLR-Institut fuer Physik der Atmosphaere GERMANY Oberpfaffenhofen D-82234.
The work will be carried out in accordance with strategic planes of ICAO international organization.
It is supposed nonfinance participation aboveraentioned and other foreign firms of international organizations in the form of discussion of results obtained and in the form of information exchange.