scientimate.winddrag#

CD, Tauwind, Ustar = scientimate.winddrag(U10, CalcMethod='wu', Rhoa=1.204, dispout='no')

Description#

Calculate wind drag coefficient, wind shear stress, and wind shear velocity

Inputs#

U10: Wind velocity in (m/s)

Wind velocity should be measured (or represents velocity) at 10 m above surface
kCalcMethod=’beji’: Drag coefficient calculation method

‘vandoren’: Van Doren (1953)

‘garratt’: Garratt (1977)

‘smith’: Smith (1977)

‘large’: Large & Pond (1981)

‘wu’: Wu (1982)

‘hwang’: Hwang (2011)

‘zijlema’: Zijlema et al. (2012)

‘cem’: Use method by Coastal Engineering Manual (CEM),

U.S. Army Corps of Engineers (2015)
Rhoa=1.204: Air density in (kg/m3)
dispout=’no’: Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

CD: Wind drag coefficient
Tauwind: Wind shear stress in (N/m^2), Tauwind=Rhoa*CD*U10^2
Ustar: Wind shear velocity in (m/s), Ustar=(CD*(U10^2))^0.5

Examples#

import scientimate as sm
import numpy as np

U10=np.arange(4,40,0.1)
CD,Tauwind,Ustar=sm.winddrag(U10,'wu',1.204,'yes')

References#

Bryant, K. M., & Akbar, M. (2016). An Exploration of Wind Stress Calculation Techniques in Hurricane Storm Surge Modeling. Journal of Marine Science and Engineering, 4(3), 58.

Chen, Y., & Yu, X. (2017). Sensitivity of storm wave modeling to wind stress evaluation methods. Journal of Advances in Modeling Earth Systems.

Dean, R. G., & Dalrymple, R. A. (1991). Water wave mechanics for engineers and scientists (Vol. 2). world scientific publishing Co Inc.

Garratt, J. R. (1977). Review of drag coefficients over oceans and continents. Monthly weather review, 105(7), 915-929.

Hwang, P. A. (2011). A note on the ocean surface roughness spectrum. Journal of Atmospheric and Oceanic Technology, 28(3), 436-443.

Large, W. G., & Pond, S. (1981). Open ocean momentum flux measurements in moderate to strong winds. Journal of physical oceanography, 11(3), 324-336.

Rogers, W. E., Babanin, A. V., & Wang, D. W. (2012). Observation-consistent input and whitecapping dissipation in a model for wind-generated surface waves: Description and simple calculations. Journal of Atmospheric and Oceanic Technology, 29(9), 1329-1346.

Smith, S. D. (1980). Wind stress and heat flux over the ocean in gale force winds. Journal of Physical Oceanography, 10(5), 709-726.

U.S. Army Corps of Engineers (2015). Coastal Engineering Manual. Engineer Manual 1110-2-1100, Washington, D.C.: U.S. Army Corps of Engineers.

VanDorn, W. G. (1953). Wind stress on an artificial pond. Journal of Marine Research, 12(3), 249-276.

Wu, J. (1982). Wind‐stress coefficients over sea surface from breeze to hurricane. Journal of Geophysical Research: Oceans, 87(C12), 9704-9706.

Zijlema, M., Van Vledder, G. P., & Holthuijsen, L. H. (2012). Bottom friction and wind drag for wave models. Coastal Engineering, 65, 19-26.

scientimate.winddrag

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