Accession Number:

ADA210253

Title:

Updating the Smith-Feddes Model

Descriptive Note:

Final rept. Sep 1984-Jun 1985

Corporate Author:

ARVIN/CALSPAN ADVANCED TECHNOLOGY CENTER BUFFALO NY

Report Date:

1985-06-01

Pagination or Media Count:

87.0

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 Navys 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.

Subject Categories:

  • Meteorology
  • Computer Programming and Software

Distribution Statement:

APPROVED FOR PUBLIC RELEASE