The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners.
As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
i
Implementation of a Discrete Dipole Approximation Scattering Database Into Community Radiative Transfer Model
-
2022
-
-
Source: Journal of Geophysical Research: Atmospheres, 127(24)
[PDF-7.50 MB]
Details:
-
Journal Title:Journal of Geophysical Research: Atmospheres
-
Personal Author:
-
NOAA Program & Office:CISESS (Cooperative Institute for Satellite Earth System Studies) ; NESDIS (National Environmental Satellite, Data, and Information Service) ; JPSS (Joint Polar Satellite System Program Office) ; NCEI (National Centers for Environmental Information) ; STAR (Center for Satellite Applications and Research)
-
Description:The Community Radiative Transfer Model (CRTM) is a fast model that requires bulk optical properties of hydrometeors in the form of lookup tables to simulate all-sky satellite radiances. Current cloud scattering lookup tables of CRTM were generated using the Mie-Lorenz theory thus assuming spherical shapes for all frozen habits, while actual clouds contain frozen hydrometeors with different shapes. The Discrete Dipole Approximation (DDA) technique is an effective technique for simulating the optical properties of non-spherical hydrometeors in the microwave region. This paper discusses the implementation and validation of a comprehensive DDA cloud scattering database into CRTM for the microwave frequencies. The original DDA database assumes total random orientation in the calculation of single scattering properties. The mass scattering parameters required by CRTM were then computed from single scattering properties and water content dependent particle size distributions. The new lookup tables eliminate the requirement for providing the effective radius as input to CRTM by using the cloud water content for the mass dimension. A collocated dataset of short-term forecasts from Integrated Forecast System of the European Center for Medium-Range Weather Forecasts and satellite microwave data was used for the evaluation of results. The results overall showed that the DDA lookup tables, in comparison with the Mie tables, greatly reduce the differences among simulated and observed values. The Mie lookup tables especially introduce excessive scattering for the channels operating below 90 GHz and low scattering for the channels above 90 GHz.
-
Keywords:
-
Source:Journal of Geophysical Research: Atmospheres, 127(24)
-
DOI:
-
ISSN:2169-897X;2169-8996;
-
Format:
-
Publisher:
-
Document Type:
-
Funding:
-
License:
-
Rights Information:CC BY
-
Compliance:Submitted
-
Main Document Checksum:
-
Download URL:
-
File Type:
