Publications

Dipu, S.; Pandithurai, G.; Panicker, A. S.; Takamura, T.; Lee, Dong-In; Kim, Dongchul (2014). Assessment and Validation of i-Skyradiometer Retrievals Using Broadband Flux and MODIS Data. ADVANCES IN METEOROLOGY, 849279.

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 (tau(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 iskyradiometer derived parameters tau(c) and R-eff have been rovided as a first guess to a radiative transfer model (SBDART) and a new retrieval algorithm has been implemented to obtain the best combination of tau(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 tau(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.

DOI:
10.1155/2014/849279

ISSN:
1687-9309; 1687-9317