Prediction of Global Cloud Cover with an Explicit Formulation
Abstract
We have successfully implemented an explicit cloud scheme within the Florida State University Global Spectral Model. This includes the liquid water mixing ratio and cloud fractions as two additional dependant variables. The main purpose of this extension is two fold: we wished to improve our global cloud forecasting capability (low, medium and high clouds) and to have a better definition of the cloud radiative effects. A band model is being used for the short and long wave radiative transfer. A major component of this study is the initialization of clouds. For this purpose we have utilized the U.S. Air Force Real-Time Nephanalysis product called RTNEPH. The microwave radiances from the U.S. Air Force fleet of DMSP satellites is another source of data. These are the special sensor microwave instruments carried by these satellites. This information provides measures of vertically integrated liquid water mixing ratios. The liquid water mixing ratios are vertically partitioned using weights from the RTNEPH; this provides an initial definition of clouds and cloud fractions. These were further initialized using the procedure of physical initialization. The impact studies of this cloud specification and initialization appear very promising.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1998
- Accession Number
- ADA360471
Entities
People
- T. N. Krishnamurti
Organizations
- Florida State University