CR 56:209-230 (2013)  -  doi:10.3354/cr01148

Mid-season climate diagnostics of jet contrail ‘outbreaks’ and implications for eastern US sky‑cover trends

Andrew M. Carleton1,2,*, Armand D. Silva1, Matthew S. Aghazarian1, Jase Bernhardt1, David J. Travis3, Jason Allard4

1Department of Geography, and 2Earth and Environmental Systems Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
3Department of Geography and Geology, University of Wisconsin - Whitewater, Whitewater, Wisconsin 53190, USA
4Department of Physics, Astronomy, and Geosciences, Valdosta State University, Valdosta, Georgia 31698, USA

ABSTRACT: The cirrus-level ‘condensation trails’ (contrails) produced by jet aircraft often occur as sub-regional-scale ‘outbreaks’ of multiple contrails, suggested as contributing to post ~1965 climate trends in parts of the US and Europe. Several previously-developed, satellite-image based contrail spatial inventories for the conterminous US (CONUS) revealed regional-scale differences in frequency. However, the use of such geographically-fixed regions was not ideal for climate studies. As a first step towards determining the potential climate impacts of contrail outbreaks for the CONUS, we develop maps of overlapping (in time, space) outbreak occurrences—‘overlaps’— by applying GIS to a recent period (2000–2002) satellite-image derived inventory for mid-season months. The higher-frequency outbreak overlap regions undergo substantial between-season vari- ations in magnitude and extent that reflect an association with upper-tropospheric temperature gradients and winds. Overlap maps generated for additional mid-season months in 2008–2009 indicate the inter-annual variability of the outbreak regionalization. To clarify the role of upper- troposphere synoptic meteorological conditions in contrail outbreak occurrence, we form compo- sites—multi-case averages—for the sub-region of maximum overlap frequency in each mid- season month. Regional and seasonal variations in the relative roles of ‘thermo-dynamic’ (here, temperature, humidity) and ‘dynamic’ (vertical motion of air, horizontal wind) controls in outbreaks are identified. Last, we demonstrate potential utility of the spatial overlap method by deriving fall- season surface station trends (1951–1993) of sky cover variables for contrasting high versus low contrail and overlap frequency grid cells in the eastern CONUS. These suggest a contrail contribu- tion to recent high-cloud increases, notably for the Midwest.

KEY WORDS: Contrails · Climate diagnostics · Regionalization · Composite analysis · Sky cover · Trends

Full text in pdf format 
Cite this article as: Carleton AM, Silva AD, Aghazarian MS, Bernhardt J, Travis DJ, Allard J (2013) Mid-season climate diagnostics of jet contrail ‘outbreaks’ and implications for eastern US sky‑cover trends. Clim Res 56:209-230

Export citation: Endnote - Reference Manager
Mail this link - Contents Mailing Lists - RSS
- -