scholarly journals Author Correction: Potential effect of bio-surfactants on sea spray generation in tropical cyclone conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Breanna Vanderplow ◽  
Alexander V. Soloviev ◽  
Cayla W. Dean ◽  
Brian K. Haus ◽  
Roger Lukas ◽  
...  

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Breanna Vanderplow ◽  
Alexander V. Soloviev ◽  
Cayla W. Dean ◽  
Brian K. Haus ◽  
Roger Lukas ◽  
...  

Abstract Despite significant improvement in computational and observational capabilities, predicting intensity and intensification of major tropical cyclones remains a challenge. In 2017 Hurricane Maria intensified to a Category 5 storm within 24 h, devastating Puerto Rico. In 2019 Hurricane Dorian, predicted to remain tropical storm, unexpectedly intensified into a Category 5 storm and destroyed the Bahamas. The official forecast and computer models were unable to predict rapid intensification of these storms. One possible reason for this is that key physics, including microscale processes at the air-sea interface, are poorly understood and parameterized in existing forecast models. Here we show that surfactants significantly affect the generation of sea spray, which provides some of the fuel for tropical cyclones and their intensification, but also provides some of the drag that limits intensity and intensification. Using a numerical model verified with a laboratory experiment, which predicts spray radii distribution starting from a 100 μm radius, we show that surfactants increase spray generation by 20–34%. We anticipate that bio-surfactants affect heat, energy, and momentum exchange through altered size distribution and concentration of sea spray, with consequences for tropical cyclone intensification or decline, particularly in areas of algal blooms and near coral reefs, as well as in areas affected by oil spills and dispersants.


2020 ◽  
Vol 70 (11) ◽  
pp. 1439-1448
Author(s):  
Hongyu Ma ◽  
Alexander V. Babanin ◽  
Fangli Qiao

2020 ◽  
Author(s):  
Sydney Sroka ◽  
Kerry Emanuel

<p>Despite the powerful influence that sea spray has on air-sea enthalpy and momentum fluxes, most state-of-the-art tropical cyclone forecast models do not incorporate the microphysics of sea spray evaporation into their boundary layer flux schemes. Since the air-sea enthalpy and momentum fluxes control a tropical cyclone’s intensification rate, increasing the accuracy of the associated bulk parameterizations is crucially important for improving forecast skill. New microphysics-based bulk parameterizations for enthalpy and momentum flux through the tropical cyclone boundary layer are developed from a set of prognostic evaporation equations and numerical simulations of evaporating, multiphase flow subject to extreme wind speeds. The microphysics-based parameterizations are computationally inexpensive and are functions of the local environmental conditions; these features allow forecast models to efficiently vary the air-sea enthalpy and momentum fluxes in space and time. By developing microphysics-based bulk parameterizations, the influence that sea spray exerts on tropical cyclone intensification can be more accurately simulated and intensity forecasts could be improved.</p>


2021 ◽  
Vol 9 (12) ◽  
pp. 1390
Author(s):  
Xingkun Xu ◽  
Joey J. Voermans ◽  
Qingxiang Liu ◽  
Il-Ju Moon ◽  
Changlong Guan ◽  
...  

While sea spray can significantly impact air–sea heat fluxes, the effect of spray produced by the interaction of wind and waves is not explicitly addressed in current operational numerical models. In the present work, the thermal effects of the sea spray were investigated for an idealized tropical cyclone (TC) through the implementation of different sea spray models into a coupled air–sea–wave numerical system. Wave-Reynolds-dependent and wave-steepness-dependent sea spray models were applied to test the sensitivity of local wind, wave, and ocean fields of this TC system. Results show that while the sensible heat fluxes decreased by up to 231 W m−2 (364%) and 159 W m−2 (251%), the latent heat fluxes increased by up to 359 W m−2 (89%) and 263 W m−2 (76%) in the simulation period, respectively. This results in an increase of the total heat fluxes by up to 135 W m−2 (32%) and 123 W m−2 (30%), respectively. Based on different sea spray models, sea spray decreases the minimum sea level pressure by up to 7 hPa (0.7%) and 8 hPa (0.8%), the maximum wind speed increases by up to 6.1 m s−1 (20%) and 5.7 m s−1 (19%), the maximum significant wave height increases by up to 1.1 m (17%) and 1.6 m (25%), and the minimum sea surface temperature decreases by up to 0.2 °C (0.8%) and 0.15 °C (0.6%), respectively. As the spray has such significant impacts on atmospheric and oceanic environments, it needs to be included in TC forecasting models.


2021 ◽  
Author(s):  
Alexander Soloviev ◽  
Breanna Vanderplow ◽  
Roger Lukas ◽  
Brian Haus ◽  
Muhammad Sami ◽  
...  

<p>Under tropical cyclones, sea spray is produced by breaking waves and direct disruption of the air-sea interface. The influence of sea spray on tropical cyclone intensity and intensification has not been well understood. There are serious questions regarding the most appropriate methods for the incorporation of sea spray in tropical cyclone models. These include momentum and enthalpy fluxes at the air-sea interface due to spray, the airborne sea-salt particles inducing boundary layer convection and clouds (Woodcock  1958, Spund  et al. 2014), and other related factors. Here, we study the effect of spray on thermodynamics of tropical cyclones using a Volume of Fluid to Discrete Phase (VOF to DPM) transition model. Due to dynamic remeshing, VOF to DPM resolves spray particles ranging in size from tens of micrometers to a few millimeters. The generated water particles that satisfy the condition of asphericity are converted into Lagrangian particles involved in a two-way interaction with the airflow. This model has been partially verified at the UM RSMAS Surge Structure Atmosphere Interaction facility (Vanderplow et al. 2020). A recent addition of the ANSYS Fluent Evaporation-Condensation model also allows us to model spray evaporation and related heat and enthalpy fluxes. A substantial part of the smallest particles was suspended in the turbulent airflow and evaporated, and thus contributed less to the total air-sea enthalpy flux. The temperature of the largest particles was close to the temperature of the water layer, which contributed more to the enthalpy flux. This resembled the effect of negative feedback on the enthalpy flux (Peng and Richter 2019). Results of the numerical simulation showed a dramatic increase of spray generation under major tropical cyclones (Cat. 3-5). Under major tropical cyclones, most sea spray (including large particles-spume) is suspended in the turbulent airflow and is then subject to the negative feedback. Consequently, in major tropical cyclones the effect of sea spray is expected to be more significant in the momentum budget rather than enthalpy flux at the air-sea interface. This result may explain the nearly constant enthalpy exchange coefficient observed in laboratory and oceanic experiments on tropical cyclones. This is also consistent with the formation of an “aerodynamic drag well” around a wind speed of 60 m/s, which can explain the process of rapid storm intensification (Soloviev et al. 2017). </p>


2021 ◽  
Author(s):  
Jialin Zhang ◽  
Wenqing Zhang ◽  
Haofeng Xia ◽  
Changlong Guan

<p>Sea spray has important influence on the evolution of tropical cyclone. The influence of sea spray in the numerical simulation and prediction of tropical cyclones is not ignorable. In order to explore the kinetic and thermodynamic effects of sea spray on tropical cyclone, the drag coefficient C<sub>D </sub>and the enthalpy transfer coefficient C<sub>K</sub> with sea spray’s effects were included in the coupled ocean-atmosphere-wave-sediment transport modeling system (COAWST). The numerical results show that, the effect of sea spray can effectively improve the simulation results of tropical cyclone path. When only the kinetic effect of sea spray is considered, the momentum flux at the surface of sea is little affected, and the upward sensible heat flux and latent heat flux are slightly increased. When kinetic and thermodynamic effects of sea spray is considered at the same time, the momentum flux is slightly increased, the upward sensible heat flux is increased, and the latent heat flux is significantly increased, the intensity of tropical cyclone is significantly enhanced, mainly due to the thermodynamic effect . Considering the kinetic and thermodynamic effects of sea spray at the same time is more effective than considering the kinetic effects of sea spray in improving the intensity simulation of tropical cyclone.</p>


2011 ◽  
Vol 139 (1) ◽  
pp. 132-152 ◽  
Author(s):  
Bin Liu ◽  
Huiqing Liu ◽  
Lian Xie ◽  
Changlong Guan ◽  
Dongliang Zhao

Abstract A coupled atmosphere–wave–ocean modeling system (CAWOMS) based on the integration of atmosphere–wave, atmosphere–ocean, and wave–current interaction processes is developed. The component models consist of the Weather Research and Forecasting (WRF) model, the Simulating Waves Nearshore (SWAN) model, and the Princeton Ocean Model (POM). The coupling between the model components is implemented by using the Model Coupling Toolkit. The CAWOMS takes into account various wave-related effects, including wave state and sea-spray-affected sea surface roughness, sea spray heat fluxes, and dissipative heating in atmosphere–wave coupling. It also considers oceanic effects such as the feedback of sea surface temperature (SST) cooling and the impact of sea surface current on wind stress in atmosphere–ocean coupling. In addition, wave–current interactions, including radiation stress and wave-induced bottom stress, are also taken into account. The CAWOMS is applied to the simulation of an idealized tropical cyclone (TC) to investigate the effects of atmosphere–wave–ocean coupling on TC intensity. Results show that atmosphere–wave coupling strengthens the TC system, while the thermodynamic coupling between the atmosphere and ocean weakens the TC as a result of the negative feedback of TC-induced SST cooling. The overall effects of atmosphere–wave–ocean coupling on TC intensity are determined by the balance between wave-related positive feedback and the negative feedback attributable to TC-induced SST cooling.


2012 ◽  
Vol 29 (4) ◽  
pp. 810-822 ◽  
Author(s):  
Xiaoping Cheng ◽  
Jianfang Fei ◽  
Xiaogang Huang ◽  
Jing Zheng

2017 ◽  
Author(s):  
Nikhil Garg ◽  
Yin Kwee Eddie Ng ◽  
Srikanth Narasimalu

Abstract. The study investigates the role of air–sea interface using numerical simulations of an Atlantic Hurricane Arthur (2014). More specifically, present study aims to discern the role ocean surface waves and sea spray play in modulating the intensity and structure of a tropical cyclone (TC). To investigate the effects of ocean surface waves and sea spray, numerical simulations were carried out using a coupled atmosphere–wave model where a sea spray microphysical model was incorporated within the coupled model. Furthermore, this study also explores how sea spray generation can be modelled using wave energy dissipation due to whitecaps, where whitecaps are considered as the primary mode of spray droplets generation at hurricane intensity wind speeds. Three different numerical simulations including sea state dependent momentum flux, sea spray mediated heat flux and combination of former two processes with sea spray mediated momentum flux were conducted. The foregoing numerical simulations were evaluated against the National Data Buoy Center (NDBC) buoy and satellite altimeter measurements as well as a control simulation using an uncoupled atmosphere model. The results indicate that the model simulations were able to capture the storm track and intensity, where the surface wave coupling results in a stronger TC. Moreover, it is also noted that when only spray mediated heat fluxes are applied in conjunction with sea state dependent momentum flux, they result in a slightly weaker TC, albeit stronger compared to the control simulation. However, when spray mediated momentum flux is applied together with spray heat fluxes, it results in a comparably stronger TC. The results presented here alludes to the role surface friction plays in intensification of a TC.


Sign in / Sign up

Export Citation Format

Share Document