Aerodynamic Roughness and Drag Measured from FLIP
Abstract
The atmospheric roughness length, 0, is an experimentally determined parameter that attempts to encapsulate the physics at the air-sea interface. For numerical modeling, 0 is central to defining the exchange of momentum across the ocean for both meteorological and oceanographic forecasting. Thus, characterizing roughness over the ocean is important for the U.S. Navy marine forecasting mission. However, 0 does not have a universal scaling with a bulk meteorological parameter, such as wind speed, sea state, etc. Using near surface profile measurements collected from the R/P FLIP (Floating Instrumentation Platform), a unique platform for science applications, this research study examines the variability in 0 as observed during the Coupled Air Sea Processes and EM ducting Research (CASPER) field study. The variability of the atmospheric friction velocity, drag coefficient, and 0 was examined, with a particular focus on evaluating the effect vertical flux divergence had on the observed scatter. After controlling for the logarithmic wind profile and non-divergent stress, a novel parameterization for 0 is presented and compared to widely used bulk relations. After examining the natural flux footprint variability, a conceptual approach to identifying spatial changes in 0 is presented and the implications for feature detection are discussed. This work holds significance for air-sea interaction modeling and the bulk parameterization of ocean surface roughness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2023
- Accession Number
- AD1213195
Entities
People
- Jackson R. Dabek
Organizations
- Naval Postgraduate School