In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 13 ( 2018-07-12), p. 9803-9822
Abstract:
Abstract. Air traffic
affects cloudiness, and thus climate, by emitting exhaust gases and
particles. The study of the evolution of contrail properties is very
challenging due to the complex interplay of vortex dynamics and the
atmospheric environment (e.g. temperature, supersaturation). Despite
substantial progress in recent years, the optical, microphysical, and
macrophysical properties of contrails and ambient cirrus during contrail
formation and subsequent ageing are still subject to large uncertainties due
to instrumental and observational limitations and the large number of
variables influencing the contrail life cycle. In this study, various
contrail cases corresponding to different aircraft types and atmospheric
conditions are investigated using a statistical method based on the in situ
optical measurements performed during the Contrail and Cirrus Experiments
(CONCERT) campaigns 2008 and 2011. The two aircraft campaigns encompass more
than 17 aircraft contrail cases. A principal component analysis (PCA) of the
angular scattering coefficients measured by the polar nephelometer is
implemented. The goal is to classify the sampled ice cloud measurements in
several clusters representative of different contrail development stages
(primary wake, young contrail, aged contrail, and cirrus). Extinction and
asymmetry coefficients, nitrogen oxide concentrations, and relative humidity
with respect to ice and particle size distributions are analysed for each
cluster to characterize the evolution of ice cloud properties during the
contrail to cirrus evolution. The PCA demonstrates that contrail optical
properties are well suited to identify and discriminate between the different
contrail growth stages and to characterize the evolution of contrail
properties.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-9803-2018
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
