Assessment and Validation of i-Skyradiometer Retrievals Using Broadband Flux and MODIS Data. (17th February 2014)

• Record Type: Journal Article
• Authors: Dipu, S.; Pandithurai, G.; Panicker, A. S.; Takamura, T.; Lee, Dong-In; Kim, Dongchul
• Other Names: Ghude Sachin D. Academic Editor.
• Is Part Of: Advances in meteorology. Volume 2014(2014)
• Publication Date: 2014-02-17
• Subjects: Meteorology -- Periodicals; Meteorology; Periodicals; 551.505
• DOI: 10.1155/2014/849279
• Languages: English
• ISSNs: 1687-9309

Abstract

Abstract : Ground-based network of cloud measurements is presently limited and there exists uncertainty in the cloud microphysical parameters derived from ground-based measurements. Bias in the i-skyradiometer derived cloud optical depth (τ c ) and droplet effective radius (R eff ) and the importance of these parameters in the parameterization of clouds in climate models have made us intend to develop a possible method for improving these parameters. A new combination method, which uses zenith sky transmittance and surface radiation measurements, has been proposed in the present study to improve the retrievals. The i-skyradiometer derived parameters τ c and R eff have been provided as a first guess to a radiative transfer model (SBDART) and a new retrieval algorithm has been implemented to obtain the best combination of τ c and R eff having minimum bias (−0.09 and −2.5) between the simulated global and diffuse fluxes at the surface with the collocated surface radiation measurements. The new retrieval method has improved τ c and R eff values compared to those derived using the transmittance only method and are in good agreement with the MODIS satellite retrievals. The study therefore suggests a possible improvement of the i-skyradiometer derived cloud parameters using observed radiation fluxes and a radiative transfer model.