elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Kontakt | English
Schriftgröße: [-] Text [+]

Surrogate cloud fields generated with the Iterative Amplitude Adapted Fourier Transform algorithm

Venema, Victor und Meyer, Steffen und Gimeno-Garcia, Sebastian und Kniffka, Anke und Simmer, Clemens und Crewell, Susanne und Löhnert, Ulrich und Trautmann, Thomas und Macke, Andreas (2006) Surrogate cloud fields generated with the Iterative Amplitude Adapted Fourier Transform algorithm. Tellus A - Dynamic Meteorology and Oceanography, 58A, Seiten 104-120. Tellus. DOI: 10.1111/j.1600-0870.2006.00160.x.

Dieses Archiv kann nicht den gesamten Text zur Verfügung stellen.

Kurzfassung

A new method of generating two-dimensional and three-dimensional cloud fields is presented, which share several important statistical properties with real measured cloud fields. Well-known algorithms such as the Fourier method and the Bounded Cascade method generate fields with a specified Fourier spectrum. The new iterative method allows for the specification of both the power spectrum and the amplitude distribution of the parameter of interest, e.g. the liquid water content or liquid water path. As such, the method is well suited to generate cloud fields based on measured data, and it is able to generate broken cloud fields. Important applications of such cloud fields are e.g. closure studies. The algorithm can be supplied with additional spatial constraints which can reduce the number of measured cases needed for such studies. In this study the suitability of the algorithm for radiative questions is evaluated by comparing the radiative properties of cloud fields from cloud resolving models of cumulus and stratocumulus with their surrogate fields at nadir, and for a solar zenith angle of 0° and 60°. The cumulus surrogate clouds ended up to be identical to the large eddy simulation (LES) clouds on which they are based, except for translations and reflections. The root mean square differences of the stratocumulus transmittance and reflectance fields are less than 0.03% of the radiative budget. The radiances and mean actinic fluxes fit better than 2%. These results demonstrate that these LES clouds are well described from a radiative point of view, using only a power spectrum together with an amplitude distribution.

Dokumentart:Zeitschriftenbeitrag
Titel:Surrogate cloud fields generated with the Iterative Amplitude Adapted Fourier Transform algorithm
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Venema, VictorMeteorological Institute of Bonn University
Meyer, SteffenLeibniz-Institut für Meereswissenschaften Kiel
Gimeno-Garcia, SebastianUniversity of Leipzig
Kniffka, AnkeUniversity of Leipzig
Simmer, ClemensMeteorological Institute of Bonn University
Crewell, SusanneMeteorological Institute of Bonn University
Löhnert, UlrichMeteorological Institute of Bonn University
Trautmann, ThomasNICHT SPEZIFIZIERT
Macke, AndreasLeibniz-Institut für Meereswissenschaften Kiel
Datum:2006
Erschienen in:Tellus A - Dynamic Meteorology and Oceanography
Referierte Publikation:Ja
In ISI Web of Science:Ja
Band:58A
DOI :10.1111/j.1600-0870.2006.00160.x
Seitenbereich:Seiten 104-120
Verlag:Tellus
Status:veröffentlicht
Stichwörter:Radiative transfer, Statistical cloud generator, Radiative properties of clouds
HGF - Forschungsbereich:Verkehr und Weltraum (alt)
HGF - Programm:Weltraum (alt)
HGF - Programmthema:W EO - Erdbeobachtung
DLR - Schwerpunkt:Weltraum
DLR - Forschungsgebiet:W EO - Erdbeobachtung
DLR - Teilgebiet (Projekt, Vorhaben):W - Vorhaben Entwicklung von Atmosphärenprozessoren (alt)
Standort: Oberpfaffenhofen
Institute & Einrichtungen:Institut für Methodik der Fernerkundung > Atmosphärenprozessoren
Hinterlegt von: Brigitte Rüba
Hinterlegt am:23 Mär 2006
Letzte Änderung:07 Apr 2010 10:07

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Copyright © 2008-2013 Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.