 |
| Titel |
Reconstruction of cloud geometry using a scanning cloud radar |
| VerfasserIn |
F. Ewald, C. Winkler, T. Zinner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 6 ; Nr. 8, no. 6 (2015-06-19), S.2491-2508 |
| Datensatznummer |
250116435
|
| Publikation (Nr.) |
 copernicus.org/amt-8-2491-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Clouds are one of the main reasons of uncertainties in the forecasts of
weather and climate. In part, this is due to limitations of remote sensing of
cloud microphysics. Present approaches often use passive spectral
measurements for the remote sensing of cloud microphysical parameters. Large
uncertainties are introduced by three-dimensional (3-D) radiative transfer
effects and cloud inhomogeneities. Such effects are largely caused by unknown
orientation of cloud sides or by shadowed areas on the cloud. Passive
ground-based remote sensing of cloud properties at high spatial resolution
could be crucially improved with this kind of additional knowledge of cloud
geometry. To this end, a method for the accurate reconstruction of 3-D cloud
geometry from cloud radar measurements is developed in this work. Using a
radar simulator and simulated passive measurements of model clouds based on a
large eddy simulation (LES), the effects of different radar scan resolutions
and varying interpolation methods are evaluated. In reality, a trade-off
between scan resolution and scan duration has to be found as clouds change
quickly. A reasonable choice is a scan resolution of 1 to 2\degree. The most
suitable interpolation procedure identified is the barycentric interpolation
method. The 3-D reconstruction method is demonstrated using radar scans of
convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud
radar. As a successful proof of concept, camera imagery collected at the
radar location is reproduced for the observed cloud cases via 3-D volume
reconstruction and 3-D radiative transfer simulation. Data sets provided by
the presented reconstruction method will aid passive spectral ground-based
measurements of cloud sides to retrieve microphysical parameters. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|