%0 Journal Article
%A Ehhalt, D. H.
%A Rohrer, F.
%A Blake, D. R.
%A Kinnison, D. E.
%A Konopka, P.
%T On the Use of nonmethane hydrocarbons for the Determination of Age Spectra in the Lower Stratosphere
%J Journal of Geophysical Research
%V 112
%@ 0148-0227
%C Washington, DC
%I Union
%M PreJuSER-57411
%P D11208
%D 2007
%Z Record converted from VDB: 12.11.2012
%X On 9 April 2001, while approaching the West Coast of the North American continent, flight 20 of the NASA TRACE P campaign penetrated deeply into a stratospheric intrusion. From measurements aboard that flight we derive vertical profiles of nonmethane hydrocarbons (NMHCs) and other short-lived trace gases in the lower stratosphere using Dichlorofluoromethane, CF2Cl2, as the altitude scale. All profiles show an exponential decrease, which permits the description of their vertical distribution by a single parameter, the scale height. These scale heights are shown to be related to the respective lifetimes in a unique fashion. Using the approximation of a 1-D diffusive model with a constant eddy diffusion coefficient, K, and assuming constant lifetimes, we establish an analytical solution for this relation. By fitting this theoretical expression to the experimental data we can estimate K and thus obtain an approximate age spectrum of the form given by Hall and Plumb (1994). A much better fit to the experimental scale heights is obtained, when we allow the lifetimes to be height-dependent and calculate the theoretical scale heights numerically from a 1-D model. An optimization also suggests a constant K, but with a value of 0.46 m(2)/s, larger than those obtained from the fit of the analytical solution. The obtained age spectra should be valid for transit times not longer than 300 days.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000247534200002
%R 10.1029/2006JD007686
%U https://juser.fz-juelich.de/record/57411