Article
Oceanography
Zhanpeng Zhuang, Yongzeng Yang, Qi Shu, Zhenya Song, Biao Zhao, Yeli Yuan
Summary: Surface waves play an important role in the vertical mixing processes in the upper ocean. This study introduces wave-generated turbulence and residue of wave transport flux as two mixing schemes, and finds that these schemes can improve sea surface temperature cooling and thermal structure in the upper ocean.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Environmental Sciences
Delei Li, Joanna Staneva, Jean-Raymond Bidlot, Sebastian Grayek, Yuchao Zhu, Baoshu Yin
Summary: This study investigates the impact of reducing surface drag at high wind speeds on modeling wind and wave conditions during the 2019 super Typhoon Lingling event. The results show that the proposed new roughness parameterization in the two-way coupling simulation performs better than previous studies in capturing the maximum wind speed of Typhoon Lingling due to reduced drag at extreme wind conditions.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Devang Falor, Bishakhdatta Gayen, Debasis Sengupta, Gregory N. Ivey
Summary: Using large-eddy simulation, we study the role of surface evaporation in modulating the diurnal mixed layer turbulence and mixing. Our findings show that surface evaporation increases the mixed layer depth and irreversible mixing through convection, both during daytime and nighttime, which leads to better prediction of dynamical variables such as sea surface salinity (SSS) and sea surface temperature (SST). These findings can help improve ocean parameterizations to enhance forecasts on a diurnal timescale.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Y. Jiang, Y. Wang, X. Tian, S. Lin, S. Chen, J. Yu, F. Chai
Summary: Frequent typhoons in the northwest Pacific cause oceanic responses, leading to changes in sea surface temperature (SST) and chlorophyll-a (Chl-a). An analysis shows that SST around the typhoon center decreases, while Chl-a increases. SST starts decreasing 3 days before the typhoon's arrival and continues to decrease for 2 days after the typhoon passes. Chl-a rapidly increases after the typhoon's arrival, reaching its maximum value 3 days later. This study provides insight into quantitatively describing typhoon-induced changes in the ocean, considering the influential oceanic environment.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Duhan Shen, Jianing Wang, Zhiyu Liu, Fan Wang
Summary: Diapycnal mixing in the upper western equatorial Pacific (WEP) is important for tropical air-sea interactions and the global climate system. The WEP is unique in water masses from both hemispheres and multi-scale processes, creating a complex mixing regime that needs to be fully characterized by observations.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Oceanography
Jingli Liu, Bo Han, Renhao Wu
Summary: This study investigates the impact of sub-mesoscale processes on the thermal and dynamical response of the upper ocean to Super Typhoon Maria. The results suggest that typhoons may destroy sub-mesoscale processes and that considering more sub-mesoscale processes can improve the accuracy of typhoon prediction. The findings highlight the importance of understanding typhoon-induced thermal and dynamical responses for improving typhoon forecasting.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Environmental Sciences
Wenqing Zhang, Rui Li, Donglin Zhu, Dongliang Zhao, Changlong Guan
Summary: Surface waves play a crucial role in regulating mixing processes in the upper ocean boundary and directly influence air-sea exchange, which is essential for predicting the intensity of tropical cyclones. This study investigates the relative and integrated impacts of wave breaking and wave orbital motion on mixing and ocean response to typhoon forcing, using modeled data from a fully coupled air-sea-wave model during typhoon Megi (2010). Results demonstrate that wave orbital motion effectively enhances turbulence mixing, deepens the mixing layer, and cools the sea surface temperature. Wave breaking modulates the mixing layer and sea surface temperature to some extent in the cold tail zone, but wave orbital motion dominates. Moreover, wave-induced mixing weakens current velocity and shear strength in the upper ocean mixing layer.
Article
Environmental Sciences
Mengtian Qiao, Anzhou Cao, Jinbao Song, Yunhe Pan, Hailun He
Summary: This study examined the response of the upper ocean to Super Typhoon Goni in 2015 and revealed a significant enhancement of diapycnal diffusivity induced by the typhoon. The results showed that Goni caused a maximum sea surface temperature cooling of 7.7 degrees C, which was greater than most typhoons. The enhanced turbulent mixing was found to be consistent with Goni-induced near-inertial waves.
Article
Oceanography
Zhanpeng Zhuang, Yeli Yuan, Quanan Zheng, Chaojie Zhou, Xinhua Zhao, Ting Zhang
Summary: The study introduces a novel turbulent mixing scheme based on non-breaking wave velocity shear module with buoyancy flux, demonstrating that the buoyancy flux can suppress the enhanced turbulent mixing induced by non-breaking waves. The simulation results from the ocean model show significant improvement in sea surface temperature and upper ocean temperature structure when compared to traditional schemes.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Meteorology & Atmospheric Sciences
Jianhua Qi, Yidan Yin, Daizhou Zhang, Hongtao Li, Lijie Dong
Summary: This study investigated the concentration and flux of biological aerosol particles in the air over oceans, specifically focusing on the difference between marginal seas and open oceans. Airborne microbes were assessed through microscope counts in samples collected during cruises in 2014 and 2016. The results showed that the concentration of airborne microbes was lower over the Northwest Pacific Ocean (NWPO) compared to Qingdao (QD), mainly due to continental sources of microbes. However, the NWPO still had a significantly higher concentration compared to the Yellow and Bohai Seas (YBS). Additionally, factors such as wind speed, direction, offshore distance, and transport distance influenced the microbe concentration over different areas. Dust events were found to increase microbe concentration and change size distribution in samples. These findings suggest that airborne microbes can be input into the ocean through atmospheric deposition, which can have important impacts on marine ecosystems.
ATMOSPHERIC RESEARCH
(2022)
Article
Environmental Sciences
Jonghyeok Jeon, Takashi Tomita
Summary: This study investigated the impact of super typhoon HAGIBIS and the Kuroshio current meander on ocean dynamics in the Northwest Pacific Ocean. The study found that the typhoon's wind stress and Ekman pumping velocity increased, leading to decreased sea temperature, shallow mixed layer depth, low sea salinity, and intensified phytoplankton bloom. These findings contribute to understanding the physical and biological mechanisms and predicting ocean anomalies.
Article
Environmental Sciences
Jie Yu, Han Zhang, Huizan Wang, Di Tian, Jiagen Li
Summary: The upper ocean structure plays a crucial role in the sea surface temperature cooling induced by tropical cyclones. This study utilizes principal component analysis to classify the upper ocean structure based on Argo profiles in the Northwest Pacific Ocean. The results reveal four types of water with distinct characteristics and varying responses to tropical cyclones, leading to differences in cyclone intensification.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Oceanography
Tomas Chor, Jacob O. Wenegrat, John Taylor
Summary: Submesoscale centrifugal-symmetric instabilities (CSIs) play an important role in transferring energy from balanced circulation to turbulent dissipation. These instabilities generate significant mixing in boundary layer flows and are implicated in the mixing and transformation of Antarctic Bottom Water. However, the mixing efficiency of CSIs remains uncertain, making estimates of mixing and energy dissipation difficult. This study uses large-eddy simulations to investigate the mixing efficiency of CSIs and finds that it can vary significantly depending on the dominant shear production mechanism. These findings suggest that it may be possible to predict the mixing efficiency using more readily measurable parameters.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Engineering, Civil
Masashi Takagi, Junichi Ninomiya, Nobuhito Mori, Tomoya Shimura, Takuya Miyashita
Summary: The study found that the fraction of wave energy taken up into the ocean as sea surface TKE flux depends on the relative angle between wind and wave direction. A new parameterization of TKE flux was proposed based on the observed results. This parameterization affects weak mixing at the ocean surface, strong mixing at the bottom of the mixed layer, and near-inertial internal waves in typhoon simulations.
COASTAL ENGINEERING JOURNAL
(2022)
Article
Mechanics
Christopher J. Howland, John R. Taylor, C. P. Caulfield
Summary: This study discusses the significant influence of turbulent mixing on physical processes in the ocean and proposes a new technique to calculate APE in periodic domains with a mean stratification. The results show that the mean dissipation rate of buoyancy variance provides a good approximation to the mean diapycnal mixing rate, but there is significant variation in quantifying mixing efficiency depending on whether laminar diffusion of a mean flow is included. The study explores how best to interpret these results in the context of quantifying diapycnal diffusivity in real oceanographic flows.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Limnology
Yang Yongzeng, Shi Yongfang, Yu Chencheng, Teng Yong, Sun Meng
JOURNAL OF OCEANOLOGY AND LIMNOLOGY
(2019)
Article
Mechanics
Shaofeng Li, Anzhou Cao, Jinbao Song, Chengcheng Yu, Juan Chen
Article
Mechanics
Shaofeng Li, Chengcheng Yu, Suhui Qian, Jinbao Song, Anzhou Cao
Summary: The influence of linear shear flow on both surface and internal freak waves was studied using a two-layer model and a nonlinear Schrodinger equation, the regions where interfacial freak waves occur were identified via analysis of modulational instability, and the effects of positive and negative vorticity on the steepness and height of the waves during supercritical up-flow and down-flow were explored.
Article
Engineering, Marine
Shuang Li, Peng Hao, Chengcheng Yu, Gengkun Wu
Summary: The study introduces a new deep neural network model, CLTS-Net, which significantly improves the accuracy of multivariate time series SWH prediction, particularly showing advantages in long-term forecasts.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Oceanography
Chengcheng Yu, Jinbao Song, Shaofeng Li, Shuang Li
Summary: A new k-omega second-moment closure (SMC) model including the Langmuir turbulence effects is proposed in this study. The performance of the new SMC model is investigated through simulations of ocean surface boundary layer and global climate. The results show significant improvements in the simulations, indicating the effectiveness of the new model.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
