A simple extension of “An alternative approach to sea surface aerodynamic roughness” by Zhiqiu Gao, Qing Wang, and Shouping Wang

Abstract

Based on the data previously collected during the Humidity Exchange over the Sea Main Experiment (HEXMAX), the methods used to parameterize aerodynamic roughness (z0), friction velocity (u*), and the neutral drag coefficient (CDN) under moderate wind speed conditions originally proposed by Gao et al. (2006) were extended by using the nondimensional significant wave height (gHs/u*2 or gHs/U10N2) instead of wave age (cp/u* or cp/U10N), where g is the acceleration of gravity, Hs is the significant wave height, U10Nis the horizontal wind speed at 10‐m height under the neutral atmospheric condition, andcp is the phase velocity of the peak wave spectrum. The results show (1) u* = 0.024U10N(gHs/U10N2)−1/4, (2) z0 = 10 × exp[−4.797(gHs/u*2)1/6] or z0 = 10 × exp[−16.613(gHs/U10N2)1/4], and (3) CDN = 0.007(gHs/u*2)−1/3 or CDN = 5.76 × 10−4(gHs/U10N2)−1/2. The present parameterization schemes were experimentally tested.

Impacts of Momentum Fluxes Modulated by Surface Waves on Near‐Inertial Motions in Tropical Cyclones

“…On the air side, the presence of surface waves affects the oceanic surface roughness felt by the airflow, which modulates the drag coefficient and determines 𝐴𝐴 𝐴𝐴𝑎𝑎 . Early studies established the dependence relationships of the drag coefficient on wave state parameters (wave age, wave height, and wave steepness) from field and laboratory observations (Edson et al, 2013;Gao et al, 2006Gao et al, , 2012Oost & Oost, 2004;Taylor & Yelland, 2001). In recent years, many researchers suggest other factors, such as wave-breaking, sea spray, and sea foam might contribute to the reduction of 𝐴𝐴 𝐴𝐴𝑑𝑑 under high wind (Donelan et al, 2004;G.…”

“…By changing the oceanic surface roughness felt by the airflow, surface waves can affect 𝐴𝐴 𝐴𝐴𝑎𝑎 (Donelan et al, 2004;Edson et al, 2013;G. Chen, Xue et al, 2013;Gao et al, 2006Gao et al, , 2012Liu et al, 2012;S. S. Chen, Zhao et al, 2013;Zhao et al, 2015).…”

Characterization of Geographical and Meteorological Parameters

“…In wetlands, [61] obtained z 0 and d from the minimization of a least square difference function based on the log wind profile equation for near-neutral stability; in wet grasslands and reed-beds, [1] estimated z 0 from eddy correlation measurements; and [78] used specific parameterizations for a Siberian bog. For water surfaces, some approaches were gathered, such as the estimation of z 0 for the sea that was validated in the laboratory by [39]; the comparison of two parameterizations for oceans by [22]; and the parameterization of z 0 for the sea by [25]. Finally, some authors have also parameterized z 0 and d for general land coverage: [92] proposed changes in Raupach parameterization using a list of values from the literature; [29] compared three previous methods and proposed to use the median; and, in the model of the European Wind Atlas [90], a parameterization of z 0 and d was introduced in four classes of coverages.…”

Parabolic dependence of the drag coefficient on wind speed from aircraft eddy-covariance measurements over the tropical Eastern Pacific

“…Parameterization of drag coefficient over the air-sea interface is essential to many aspects of air-sea interaction, which is vital for atmospheric, oceanic and surface wave prediction models, as well as climate modeling. Early studies established different linear relationships between drag coefficient and wind speed [1][2][3] and dependence relationships of drag coefficient on wind speed and wave status parameters [4][5][6][7] (wave age, wave height, and wave steepness) from field and laboratory observations. However, these studies are mostly only applicable to low-to-moderate wind conditions, and they are unsuitable for high wind conditions due to effects of sea spray droplets produced by bursting bubbles and/or wind tearing breaking wave crests 8 .…”