|
Titel |
Interdependence of tropical cirrus properties and their variability |
VerfasserIn |
S. V. Sunilkumar, K. Parameswaran, Bijoy V. Thampi |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 26, no. 3 ; Nr. 26, no. 3 (2008-03-26), S.413-429 |
Datensatznummer |
250016034
|
Publikation (Nr.) |
copernicus.org/angeo-26-413-2008.pdf |
|
|
|
Zusammenfassung |
The mean properties of tropical cirrus, such as cloud top, cloud base, optic
centre, cloud strength/optical depth, asymmetry factor and cloud
depolarization, as well as their heterogeneities are examined using lidar
observations over 281 nights from a tropical station Gadanki (13.5° N,
79.2° E) during the period 1998–2002. This study shows that as the cloud
optical depth (τc) increases the cloud becomes more asymmetric in
its scattering property. The amount of asymmetry is less than 2% for very
low values of (τc and increases nonlinearly with an increase in
(τc. The physical properties of these clouds also show significant
variation with different time scales during the course of each night. On
average, while the short-term variations in (τc are in opposite
phase with those of the asymmetry factor (ξ) and volume depolarization
ratio (δ), the long-term variation in (τc extending over a
night are found to be in opposite phase with that of ξ and in-phase
with that of δ. The short-term variations in δ and (τc were
attributed to possible changes in the cloud particle
orientation and the long period variations to cloud evolution process. The
value of δ shows a pronounced variation along the vertical, with low
values near the cloud top and cloud base and high values in the middle,
which is attributed to the cloud dynamics. |
|
|
Teil von |
|
|
|
|
|
|