Research Summaries

Back Aircraft Observations for Improved Physical Parameterization for Seasonal Prediction

Fiscal Year 2011
Division Graduate School of Engineering & Applied Science
Department Meteorology
Investigator(s) Wang, Qing
Sponsor Office of Naval Research (Navy)
Summary We propose to deploy the CIRPAS Twin Otter in the stratocumulus regimes off the California coast with the objective of examining boundary layer cloud and turbulence parameterizations for applications in medium-range forecast models. Our planned observations will target the statistical parameterization method using the probability distribution functions (PDF) of dynamic and thermodynamic variables in cloudy boundary layers with various cloud fractions. In recent years, PDF-related cloud parameterizations have been developed from various research groups, mostly using larger eddy simulations and with a few evaluated against limited aircraft observations. It is considered that the PDF approach may be the answer for a 'unified' cloud parameterization applicable for frequently observed boundary layer clouds. However, some Large Eddy Simulation (LES) studies also indicate the difficulties in identifying the functional form of the PDF and hence question the concept of the 'unified' approach. There are still questions remaining as to whether LES is an adequate tool for such an approach and whether measurement/sampling issues in previous observations may mislead the results of the observational analyses. This project intends to explore the PDF approach further with measurements specifically designed to examine the PDF parameterizations. The areal mapping sampling strategy is intended to improve the statistical significance of the measurements, particularly on cloud fractions.
Keywords
Publications Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal