View in EDS

Sensitivity of contrail coverage and contrail radiative forcing to selected key parameters

Saved in:
Bibliographic Details
Title: Sensitivity of contrail coverage and contrail radiative forcing to selected key parameters
Authors: Frömming, C.1 christine.froemming@dlr.de, Ponater, M.1, Burkhardt, U.1, Stenke, A.2, Pechtl, S.3, Sausen, R.1
Source: Atmospheric Environment. Mar2011, Vol. 45 Issue 7, p1483-1490. 8p.
Subject Terms: *Condensation trails, *Radiative forcing, *Climate change, *Environmental impact analysis, Aeronautics, Estimates, Seasons, Calibration
Abstract: Abstract: Estimates of global mean radiative forcing of line-shaped contrails are associated with a high level of uncertainty. Recent estimates for present day air traffic range from 5.4mWm−2 to 25.6mWm−2. The aim of this research paper is to systematically study the sensitivity of contrail radiative forcing to selected key parameters and to highlight the most important factors for this large uncertainty range, while employing an improved version of the ECHAM climate model. The dominating parameters on contrail radiative forcing are found to be the detection threshold used for calibrating contrail coverage to observations, and the mean optical depth. Assuming a detection threshold of 0.05 instead of 0.02 yields an increase of the total coverage, resulting in a 146% increase of global mean contrail radiative forcing. Employing a globally constant optical depth of up to 0.3, increases the net radiative forcing by 140% over the reference case which has a mean optical depth of 0.08. An upgraded parameterisation of potential contrail coverage yields a significantly larger amount of tropical contrails, increasing the contrail radiative forcing by 53%. The calibration to an alternative observation region along with the assumption of a higher visibility threshold yields an increase of the radiative forcing by 46%. Moderate sensitivity of global contrail radiative forcing (∼15%) is found for an improvement of model climate and for changes in particle shape. The air traffic inventory, air traffic density parameter, and the diurnal variation of air traffic have only a small effect on global and annual mean contrail radiative forcing, but their influence on regional and seasonal contrail radiative forcing may nevertheless be important. [Copyright &y& Elsevier]
Copyright of Atmospheric Environment is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
Description
Abstract:Abstract: Estimates of global mean radiative forcing of line-shaped contrails are associated with a high level of uncertainty. Recent estimates for present day air traffic range from 5.4mWm−2 to 25.6mWm−2. The aim of this research paper is to systematically study the sensitivity of contrail radiative forcing to selected key parameters and to highlight the most important factors for this large uncertainty range, while employing an improved version of the ECHAM climate model. The dominating parameters on contrail radiative forcing are found to be the detection threshold used for calibrating contrail coverage to observations, and the mean optical depth. Assuming a detection threshold of 0.05 instead of 0.02 yields an increase of the total coverage, resulting in a 146% increase of global mean contrail radiative forcing. Employing a globally constant optical depth of up to 0.3, increases the net radiative forcing by 140% over the reference case which has a mean optical depth of 0.08. An upgraded parameterisation of potential contrail coverage yields a significantly larger amount of tropical contrails, increasing the contrail radiative forcing by 53%. The calibration to an alternative observation region along with the assumption of a higher visibility threshold yields an increase of the radiative forcing by 46%. Moderate sensitivity of global contrail radiative forcing (∼15%) is found for an improvement of model climate and for changes in particle shape. The air traffic inventory, air traffic density parameter, and the diurnal variation of air traffic have only a small effect on global and annual mean contrail radiative forcing, but their influence on regional and seasonal contrail radiative forcing may nevertheless be important. [Copyright &y& Elsevier]
ISSN:13522310
DOI:10.1016/j.atmosenv.2010.11.033