Impacts of the Wave-Dependent Sea Spray Parameterizations on Air–Sea–Wave Coupled Modeling under an Idealized Tropical Cyclone

Abstract

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.

An Improved Parameterization of Sea Spray-Mediated Heat Flux Using Gaussian Quadrature: Case Studies with a Coupled CFSv2.0-WW3 System

“…Andreas and Emanuel (2001) implemented sea spray-mediated heat flux and momentum flux parameterizations into a simple tropical cyclone model, and found that the sea spray-induced heat flux significantly enhances the tropical cyclone intensity, offsetting the negative effect of enhanced surface drag by strong wind and waves. The similar enhancement of tropical cyclone intensity was also shown in recent regional coupling systems by including sea spray-mediated heat flux (Xu et al, 2021a;Liu et al, 2012;Garg et al, 2018;Zhao et al, 2017). In the First Institute of Oceanography Earth System Model, Bao et al (2020) first incorporated the sea spray-mediated heat flux in global climate simulation.…”

“…A5-A6 of Appendix A), therefore it is difficult to apply A92 directly in coupled modeling systems. A15 (Andreas et al, 2015) developed a fast algorithm by using a single representative droplet radius (details in Appendix B), which was widely adopted in recent reginal and global coupling systems (Xu et al, 2021a;Liu et al, 2012;Garg et al, 2018;Zhao et al, 2017;Song et al, 2022;Bao et al, 2020). In this study, we apply a 3-node GQ method (details in Appendix C) to develop a new fast algorithm to approximate the full-size spectral integral of A92.…”

“…Since the parameterization of sea spray-mediated heat flux derived from observations requires fullsize spectral integral and demands huge amount of computational time (Andreas, 1989(Andreas, , 1990(Andreas, , 1992Andreas et al, 2015), a simplified parameterization based on a single radius of sea spray droplets (Andreas et al, 2015;Andreas et al, 2008) is widely used in atmosphere-ocean coupling systems (Xu et al, 2021a;Liu et al, 2012;Garg et al, 2018;Zhao et al, 2017;Song et al, 2022;Bao et al, 2020), and apt to produce significant biases. To reduce biases induced by the single radius of sea spray droplets, we develop a new parameterization of sea spray-mediated heat flux based on the Gaussian Quadrature (GQ) method, a fast and accurate way to calculate spectral integral.…”

Why Do Eastern North Pacific Hurricanes Intensify More and Faster than Their Western-Counterpart Typhoons with Less Ocean Energy?

“…This provides a condition unfavorable for sea spray generation, because of the reduction of both wind forcing and wave breaking (Xu et al 2021a). Thus, it has negative feedback on intensification for a larger TC since an increase in sea spray is known to increase the sea-air enthalpy transfer (Andreas and Emanuel 2001;Bao et al 2011;Wang et al 2001;Xu et al 2021b). Second, increased significant wave height and wavelength enhances the TC-induced sea-surface cooling (Fig.…”

Sea Spray Impacts on Tropical Cyclone Olwyn Using a Coupled Atmosphere‐Ocean‐Wave Model

“…One of the primary reasons is the lack of sufficient understanding of the basic physical mechanisms that generate, drive, and maintain TCs (Chan, 2005; Chan & Kepert, 2010; Elsner et al., 2008). In particular, one external physical process that might affect the intensity of a TC is sea spray (Andreas & Emanuel, 2001; Gall et al., 2008; Xu, Voermans, Liu, et al., 2021).…”