Aircraft Observations for Improved Physical Parameterization for Seasonal Prediction
NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
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The long-term goal of this project is to improve the representation of fractional low-level clouds in the medium-range forecast models. The objectives of the NPS project is to understand the physical processes involved in boundary layers covered by fractional cloudiness and to make extensive measurements specially aimed at quantifying various statistical quantities needed to examine and develop PDF-based cloud and turbulence parameterizations. The objectives of the NRL project are to obtain measurements of the solar and IR irradiance throughout the cloudy boundary layer in order to characterize the solar and IR radiative energy environment. In particular, to obtain vertical profiles of the solar and IR irradiance throughout the boundary layer to quantify the role of the solar and IR heatingcooling rate profiles on marine stratus. The NPS work within this project consists of two parts. First, we examined data from previous field programs, in which we first looked into the uncertainties in defining 1-dimensional cloud fraction from limited number of observations using three independent methods. We then explored the cloud and thermodynamic conditions that results in outstanding values of skewness and turbulent fluxes to illustrate the complication of the PDF approach in various boundary layer cloud conditions. This part of the research helps us to identify specific issues that require further observations and to design new measurement strategies. The second part is the new field measurements using the CIRPAS Twin Otter, which occurred in AugustSeptember 2012. The new field measurements will be referred to as the Unified Physical Parameterization for Extended Forecast 2012 field project UPPEF2012.