Open AccessOn the Need to Modify the Sea Surface Roughness Formulation over Shallow Waters
Author(s) -
Pedro A. Jiménez,
Jimy Dudhia
Publication year - 2018
Publication title -
journal of applied meteorology and climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.079
H-Index - 134
eISSN - 1558-8432
pISSN - 1558-8424
DOI - 10.1175/jamc-d-17-0137.1
Subject(s) - roughness length , mesoscale meteorology , drag , wind stress , planetary boundary layer , waves and shallow water , turbulence , atmosphere (unit) , range (aeronautics) , boundary layer , environmental science , wind speed , surface roughness , geology , surface finish , meteorology , atmospheric sciences , wind profile power law , climatology , mechanics , oceanography , materials science , physics , composite material
The wind stress formulation in an atmospheric model over shallow waters is investigated using year-long observations of the wind profile within the first 100 m of the atmosphere and mesoscale simulations. The model experiments use a range of planetary boundary layer parameterizations to quantify the uncertainty related to the turbulent closure assumptions and thus to isolate the dominant influence of the surface roughness formulation. Results indicate that a positive wind speed bias exists when common open-ocean formulations for roughness are adopted for a region with a water depth of 30 m. Imposition of a wind stress formulation that is consistent with previous shallow-water estimates is necessary to reconcile model wind speeds with observations, providing modeling evidence that supports the increase of surface drag over shallow waters. The possibility of including water depth in the parameterization of roughness length is examined.