Updating the Smith-Feddes Model
Abstract
The Smith-Feddes (S-F) model, which provided cloud and precipitation water content and drop-size distribution from 3DNEPH cloud input, was modified to accept cloud information in the RTNEPH format produced at the Air Force Global Weather Center and to incorporate more rigorous specification of microphysics. The computer code for this modified model was installed for operational use at the Navy's Fleet Numerical Oceanography Center (FNOC). The cloud microphysics of the model, which included a table of cloud maximum condensed moisture by temperature, specification of the relative amount of supercooled water and ice in cloud, and designation of drop-size distributions in cloud, were examined for overall adequacy, accuracy and representativeness with respect to observations acquired since development (1973) of the model. Primarily because the S-F condensed moisture table specified same water content value for cumulus clouds without regard to cloud depth, we modified the model so that it computes condensed moisture content via moist adiabatic ascent for all noncirriform clouds. For cumuliform clouds the adiabatic water content is reduced to account for entrainment of environmental air.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1985
- Accession Number
- ADA210253
Entities
People
- C. W. Rogers
- Eugene J. Mack
- James T. Hanley
Organizations
- Calspan