Increased light, moderate, and severe clear-air turbulence in response to climate change
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Anthropogenic climate change is expected to strengthen the vertical wind shears at aircraft cruising altitudes within the atmospheric jet streams. Such a strengthening would increase the prevalence of the shear instabilities that generate clear-air turbulence. Climate modelling studies have indicated that the amount of moderate-or-greater clear-air turbulence on transatlantic flight routes in winter will increase significantly in future as the climate changes. However, the individual responses of light, moderate, and severe clear-air turbulence have not previously been studied, despite their importance for aircraft operations. Here, we use climate model simulations to analyse the transatlantic wintertime clear-air turbulence response to climate change in five aviation-relevant turbulence strength categories. We find that the probability distributions for an ensemble of 21 clear-air turbulence diagnostics generally gain probability in their right-hand tails when the atmospheric carbon dioxide concentration is doubled. By converting the diagnostics into eddy dissipation rates, we find that the ensembleaverage airspace volume containing light clear-air turbulence increases by 59% (with an intra-ensemble range of 43%–68%), light-to-moderate by 75% (39%–96%), moderate by 94% (37%–118%), moderate-to-severe by 127% (30%–170%), and severe by 149% (36%–188%). These results suggest that the prevalence of transatlantic wintertime clear-air turbulence will increase significantly in all aviation-relevant strength categories as the climate changes.
Key wordsturbulence climate change aviation jet stream
The author is financially supported through a University Research Fellowship from the Royal Society (reference UF130571). He thanks Jenny LIN for her invitation and encouragement to write an article on aviation turbulence. The author acknowledges the modelling groups, the Program for Climate Model Diagnosis and Intercomparison, and the World Climate Research Programme’sWorking Group on Coupled Modelling for their roles in making available the climate model data. Support of this dataset is provided by the Office of Science, US Department of Energy. The constructive comments of four reviewers are gratefully acknowledged.
- Brown, R., 1973: New indices to locate clear-air turbulence. Meteor. Mag., 102, 347–361.Google Scholar
- Clark, T. L., W. D. Hall, R. M. Kerr, D. Middleton, L. Radke, F. M. Ralph, P. J. Neiman, and D. Levinson, 2000: Origins of aircraft-damaging clear-air turbulence during the 9 December 1992 Colorado downslope windstorm: Numerical simulations and comparison with observations. J. Atmos. Sci., 57, 1105–1131.CrossRefGoogle Scholar
- Endlich, R. M., 1964: The mesoscale structure of some regions of clear-air turbulence. J. Atmos. Sci., 3, 261–276.Google Scholar
- FAA, 2006: Preventing injuries caused by turbulence. Advisory Circular 120-88A, Federal Aviation Administration, Washington, DC.Google Scholar
- CAO, 2015: International Civil Aviation Organization (ICAO) Second High-Level Safety Conference (HLSC), Montreal, Canada, 2–5 February 2015, Working Paper on Extreme Meteorological Conditions (HLSC/15-WP/36). [Available online from www.icao.int/ Meetings/HLSC2015/Documents/WP/wp036 en.pdf].Google Scholar
- Karpechko, A., A. Lukyanov, E. Kyrö, S. Khaikin, L. Korshunov, R. Kivi, and H. Vömel, 2007: The water vapour distribution in the Arctic lowermost stratosphere during the LAUTLOS campaign and related transport processes including stratosphere–troposphere exchange. Atmos. Chem. Phys., 7, 107–119.CrossRefGoogle Scholar
- Kim, B., and Coauthors, 2005: System for assessing Aviation’s Global Emissions (SAGE), Version 1.5, Technical Manual FAA-EE-2005-01, Federal Aviation Administration, Washington, DC.Google Scholar
- Krozel, J., V. Klimenko, and R. Sharman, 2011: Analysis of clear-air turbulence avoidance maneuvers. Air Traffic Control Quarterly, 19, 147–168.Google Scholar
- Lee, L., 2013: A climatological study of clear air turbulence over the North Atlantic. Master’s thesis, Dept. of Earth Sciences, Uppsala University.Google Scholar
- Malwitz, A., and Coauthors, 2005: System for assessing Aviation’s Global Emissions (SAGE), Version 1.5, Validation Assessment, Model Assumptions and Uncertainties. Tech. Rep. FAA-AA-EE-2005-03, Federal Aviation Administration, Washington, DC.Google Scholar
- Meehl, G. A., and Coauthors, 2007: Global climate projections. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Solomon et al., Eds., Cambridge University Press, 747–846.Google Scholar
- Penner, J. E., D. H. Lister, D. J. Griggs, D. J. Dokken, and M. Mc-Farland, 1999: Intergovernmental Panel on Climate Change (IPCC) special report: Aviation and the global atmosphere. Cambridge University Press, 373 pp.Google Scholar
- Puempel, H., and P. D. Williams, 2016: The impacts of climate change on aviation: Scientific challenges and adaptation pathways. ICAO Environmental Report 2016: On Board A Sustainable Future, 205–207.Google Scholar
- Reiter, E. R., 1963: Jet-stream Meteorology. University of Chicago Press, 515 pp.Google Scholar
- Sharman, R. D., and J. M. Pearson, 2017: Prediction of energy dissipation rates for aviation turbulence. Part I: Forecasting nonconvective turbulence. J. Appl. Meteor. Climatol., 56, 317–337.Google Scholar
- Warner, M., 2013: Boeing: Current market outlook 2013–2032. Boeing Commercial Airplanes, Seattle, WA.Google Scholar
- Williams, P. D., P. L. Read, and T. W. N. Haine, 2003: Spontaneous generation and impact of inertia–gravity waves in a stratified, two-layer shear flow. Geophys. Res. Lett., 30, 2255.Google Scholar
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