TY - JOUR
T1 - Geostrophic Drag Law in Conventionally Neutral Atmospheric Boundary Layer
T2 - Simplified Parametrization and Numerical Validation
AU - Liu, Luoqin
AU - Lu, Xiyun
AU - Stevens, Richard J.A.M.
N1 - Publisher Copyright:
© The Author(s), under exclusive licence to Springer Nature B.V. 2024.
PY - 2024/8/10
Y1 - 2024/8/10
N2 - This study investigates the parameterization of the geostrophic drag law (GDL) for conventionally neutral atmospheric boundary layers (CNBLs). Utilizing large eddy simulations, we confirm that in CNBLs capped by a potential temperature inversion, the boundary-layer height scales as u∗/Nf, where u∗ represents the friction velocity, N the free-atmosphere Brunt–Väisälä frequency, and f the Coriolis parameter. Additionally, we confirm that the wind gradients normalized by the Brunt–Väisälä frequency have universal profiles above the surface layer. Leveraging these physical insights, we derived analytical expressions for the GDL coefficients A and B, correcting the earlier form of Zilitinkevich and Esau (Q J R Meteorol Soc 131:1863–1892, 2005). These expressions for A and B have been validated numerically, ensuring their accuracy in representing the geostrophic drag coefficient u∗/G (G is the geostrophic wind speed) and the cross-isobaric angle. This work extends the range for which the GDL has been validated up to u∗/G=[0.019,0.047]. This further supports the application of GDL to CNBLs over a broader range of u∗/G, which is useful for meteorological applications such as wind energy.
AB - This study investigates the parameterization of the geostrophic drag law (GDL) for conventionally neutral atmospheric boundary layers (CNBLs). Utilizing large eddy simulations, we confirm that in CNBLs capped by a potential temperature inversion, the boundary-layer height scales as u∗/Nf, where u∗ represents the friction velocity, N the free-atmosphere Brunt–Väisälä frequency, and f the Coriolis parameter. Additionally, we confirm that the wind gradients normalized by the Brunt–Väisälä frequency have universal profiles above the surface layer. Leveraging these physical insights, we derived analytical expressions for the GDL coefficients A and B, correcting the earlier form of Zilitinkevich and Esau (Q J R Meteorol Soc 131:1863–1892, 2005). These expressions for A and B have been validated numerically, ensuring their accuracy in representing the geostrophic drag coefficient u∗/G (G is the geostrophic wind speed) and the cross-isobaric angle. This work extends the range for which the GDL has been validated up to u∗/G=[0.019,0.047]. This further supports the application of GDL to CNBLs over a broader range of u∗/G, which is useful for meteorological applications such as wind energy.
KW - 2024 OA procedure
KW - Conventionally neutral
KW - Geostrophic drag law
KW - Large eddy simulations
KW - Atmospheric boundary layer
UR - http://www.scopus.com/inward/record.url?scp=85201186769&partnerID=8YFLogxK
U2 - 10.1007/s10546-024-00878-6
DO - 10.1007/s10546-024-00878-6
M3 - Article
AN - SCOPUS:85201186769
SN - 0006-8314
VL - 190
JO - Boundary-Layer Meteorology
JF - Boundary-Layer Meteorology
IS - 8
M1 - 37
ER -