The direct impact of aviation on climate via the emission of greenhouse gases and particles is small relative to other anthropogenic sources. However, the potential impact of aviation on climate is unique because aviation associated sources occur at high altitudes where other anthropogenic sources are absent, and aircraft are the only major source of emissions above the Arctic Circle. The climatic and chemical impact of aviation emissions and the resulting contrails and contrail-enhanced cirrus in the troposphere and stratosphere may be significant. There are large uncertainties in relating aviation emissions to changes in radiative forcing or surface temperature, especially for contrail-associated pathways. The research seeks to find robust relationships between aircraft emissions and the properties of contrails generated by aircraft under a variety of atmospheric conditions using both a high-resolution large-eddy simulation model and telescoping global-regional climate model.

ANTICIPATED OUTCOME

A better understanding of the effects of aircrafft exhaust on global and regional climate, contrails, clouds, and atmospheric composition.

PARTICIPATING UNIVERSITY

Stanford University

LEAD INVESTIGATORS

Mark Jacobson, Director, Atmosphere/Energy Program, Department of Civil and Environmental Engineering, Stanford University, jacobson@stanford.edu

Sanjiva Lele, Professor of Aeronautics and Astronautics and of Mechanical Engineering, Department of Aeronautics and Astronautics, Stanford University lele@stanford.edu

FAA PROGRAM MANAGER

Rangasayi Halthore, rangasayi.halthore@faa.gov

DOWNLOADS/REPORTS

• Poster: Modeling Persistent Contrails in a Large Eddy Simulation and a Global Climate Model, A. Naiman, S. Lele, J. Wilkerson, M. Jacobson. Presented at the American Geophysical Union 2009 Fall Meeting.
• Analysis of emission data from global commercial aviation: 2004 and 2006. J. T. Wilkerson, M. Z. Jacobson, A. Malwitz, S. Balasubramanian, R. Wayson, G. Fleming, A. D. Naiman, S. K. Lele, July 2010, Atmospheric Chemistry and Physics. Download (pdf 1M)
• Parameterization of subgrid plume dilution for use in large-scale atmospheric simulations. A. D. Naiman, S. K. Lele, J. T. Wilkerson, and M. Z. Jacobson, March 2010, Atmospheric Chemistry and Physics. Download (pdf 557K)
• Climate Impacts of Aviation: PARTNER final report on subtask: Large Eddy Simulations of Contrails. Sanjiva K. Lele, Richard C. Miake-Lye, September 2008. Report No. PARTNER-COE-2008-007 Download (pdf 2.8M)
• Workshop on the Impacts of Aviation on Climate Change: A report on findings and recommendations, June 7-9, 2006, Cambridge, MA. Donald Wuebbles, et al. August, 2006. (Report No. PARTNER-COE-2006-04) Download full report (.pdf 2M) Download executive summary (.pdf 956K)
• Workshop on the Impacts of Aviation on Climate Change. Presented at the ICAO Committee on Aviation Environmental Protection 7th Meeting, 5-16 February 2007, Montréal, Canada Download (.pdf 280K)