 |
| Titel |
Thin and subvisible cirrus and contrails in a subsaturated environment |
| VerfasserIn |
M. Kübbeler, M. Hildebrandt, J. Meyer, C. Schiller, Th. Hamburger, T. Jurkat, A. Minikin, A. Petzold, M. Rautenhaus, H. Schlager, U. Schumann, C. Voigt, P. Spichtinger, J.-F. Gayet, C. Gourbeyre, M. Krämer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 12 ; Nr. 11, no. 12 (2011-06-22), S.5853-5865 |
| Datensatznummer |
250009862
|
| Publikation (Nr.) |
 copernicus.org/acp-11-5853-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| The frequency of occurrence of cirrus clouds and contrails, their
life time, ice crystal size spectra and thus their radiative
properties depend strongly on the ambient distribution of the
relative humidity with respect to ice (RHice). Ice clouds do not
form below a certain supersaturation and both cirrus and contrails
need at least saturation conditions to persist over a longer period.
Under subsaturated conditions, cirrus and contrails should dissipate. During the mid-latitude aircraft experiment CONCERT 2008 (CONtrail
and Cirrus ExpeRimenT), RHice and ice crystals were measured in
cirrus and contrails. Here, we present results from 2.3/1.7 h
of observation in cirrus/contrails during 6 flights. Thin and
subvisible cirrus with contrails embedded therein have been detected
frequently in a subsaturated environment. Nevertheless, ice crystals up to radii of 50 μm and larger, but
with low number densities were often observed inside the contrails
as well as in the cirrus. Analysis of the meteorological situation
indicates that the crystals in the contrails were entrained from the
thin/subvisible cirrus clouds, which emerged in frontal systems with
low updrafts. From model simulations of cirrus evaporation times it
follows that such thin/subvisible cirrus can exist for time periods
of a couple of hours and longer in a subsaturated environment and
thus may represent a considerable part of the cirrus coverage. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|