最新科研进展
On the upward flux of sea-spray spume droplets in high-wind conditions
Authors:
Lin Wu1, Xueling Cheng1, Qingcun Zeng2, Jiangbo Jin2, Jian Huang3, and Yerong Feng4
1 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China,
2 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China,
3 Institute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou, China,
4 Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou, China
Abstract:
It has been speculated that the spume droplets torn off from ocean waves in high wind speeds (larger than about 9 m s-1) enhance air-seafluxes. However, the vertical transport of spume droplets in the high-wind atmospheric boundary layer (ABL) is little researched and lacks the support of numerical simulations. Based on observational data and the characteristics of high-wind ABL above the ocean, the vertical transport of spume droplets is studied and simulated. It is revealed that the existence of gusty wind with coherent structure during high winds is favorable for the vertical transport of the large-size droplets. The trajectories of 1000 spume droplets with different sizes under different wind speeds in the range 10–35 m s-1 are calculated, and the uplifting fraction of spume droplets that can reach the 100 m height in the ABL is parameterized by using a nondimensional factor U102/(r80g), where U10 is the wind speed at 10 m height, r80 the equilibrium radius of droplet at an equivalent 80% relative humidity, and g the gravitational acceleration. Then, the upwardflux of large-size spume droplets and the mass concentration at 100 m height are evaluated. These numerical results are comparable to some observational data and show that the large-size spume droplets can be entrained into the ABL during high winds and then contribute to the air-sea mass fluxes.
Key Points:
？ Vertical transports of sea-spray spume droplets in high winds are studied
？ Sea-spray spume droplets canfly into the 100 m height with the effects of gusty wind in high winds
？ The effective upwardflux and mass concentration of sea-spray spume droplets at 100 m are estimated
Citation:
Wu, L., X. Cheng, Q. Zeng, J.B. Jin, J. Huang, and Y. Feng (2017), On the upward flux of sea-spray spume droplets in highwind conditions, J. Geophys. Res. Atmos., 122, doi:10.1002/2016JD026369.
