Article
Oceanography
Y. A. Eddebbar, A. C. Subramanian, D. B. Whitt, M. C. Long, A. Verdy, M. R. Mazloff, M. A. Merrifield
Summary: Tropical instability vortices (TIVs) have significant impacts on the three-dimensional structure and variability of dissolved oxygen in the upper equatorial Pacific water column. The effects of TIVs on equatorial Pacific oxygen balance are mainly dominated by eddy-advection and mixing, while indirect effects on oxygen consumption play a minor role. Eddies influence oxygen distributions and variability through transient displacements of isopycnals and transport of oxygen through eddy trapping, stirring, and subduction.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
L. Maillard, J. Boucharel, M. F. Stuecker, F. -F. Jin, L. Renault
Summary: This study investigates the effects of tropical instability waves (TIWs) on the seasonal cycle of the eastern Pacific Ocean. The results show that TIWs warm the equatorial waters and reduce the amplitude of the seasonal cycle in upper ocean temperatures. Additionally, TIWs stabilize the upper part of the Equatorial Undercurrent (EUC) and prevent unrealistic re-intensification.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Sining Ling, Riyu Lu
Summary: This study investigates the impact of El Nino-Southern Oscillation (ENSO) on the seasonal evolution of the Asian-Pacific summer monsoon. The results show that El Nino delays the seasonal march of the monsoon and Asian jet, while La Nina does not exhibit clear variations. These variations can be explained by the changes in tropical tropospheric temperatures and meridional temperature gradient.
JOURNAL OF CLIMATE
(2022)
Article
Oceanography
Lina Yang, Raghu Murtugudde, Shaojun Zheng, Peng Liang, Wei Tan, Lei Wang, Baoxin Feng, Tianyu Zhang
Summary: The tropical Pacific currents were studied using gridded Argo data. Three branches of the South Equatorial Current (SEC) were identified, with different seasonal variations and westward propagation characteristics. A simple analytical Rossby wave model successfully simulated most of the seasonal variations, emphasizing the importance of first-mode baroclinic, linear Rossby waves. However, a nonlinear model involving higher baroclinic modes is suggested to explain certain variations in the central-east Pacific.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Meteorology & Atmospheric Sciences
Yu Zhang, Shi-Yun Yu, Shang-Ping Xie, Dillon J. Amaya, Qihua Peng, Yu Kosaka, Xiaopei Lin, Jun-Chao Yang, Sarah M. Larson, Arthur J. Miller, Lei Fan
Summary: This study focuses on the equatorial Pacific decadal variability (EPDV), revealing that ocean dynamics play a crucial role in EPDV. By using mechanically decoupled simulation and fully coupled dynamic ocean model, it is demonstrated that mean ocean circulation damps EPDV through upwelling, while anomalous wind-driven ocean circulation amplifies EPDV. The study also identifies the zonal dipole mode in the tropical Pacific as the origin of EPDV, which is strongly associated with decadal modulation of ENSO amplitude.
Article
Meteorology & Atmospheric Sciences
Yu Zhang, Shiyun Yu, Dillon J. Amaya, Yu Kosaka, Sarah M. Larson, Xudong Wang, Jun-Chao Yang, Malte F. Stuecker, Shang-Ping Xie, Arthur J. Miller, Xiaopei Lin
Summary: Investigating the North PMM and South PMM through a mechanically decoupled climate model simulation revealed new insights into their associated atmospheric forcing and response processes.
JOURNAL OF CLIMATE
(2021)
Article
Oceanography
Anna-Lena Deppenmeier, Frank O. Bryan, William S. Kessler, LuAnne Thompson
Summary: This study investigates the seasonal and subseasonal variability of cross-isothermal flow in the cold tongue of the equatorial Pacific. Diabatic upwelling is present throughout the year, with solar-penetration-driven diabatic upwelling strongest in spring and vertical mixing dominating during the rest of the year. The passage of tropical instability waves enhances the diabatic upwelling.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Meteorology & Atmospheric Sciences
Mathias Zeller, Shayne McGregor, Erik van Sebille, Antonietta Capotondi, Paul Spence
Summary: Understanding mechanisms of tropical Pacific decadal variability is crucial, as it can help differentiate between natural climate variability and human-induced climate change due to strong global teleconnections in the region. Using an ocean general circulation model, researchers found that advection of density compensated temperature anomalies from the eastern subtropics may contribute to TPDV, with a majority originating from the Southern Hemisphere and taking over 4 years to reach the equator.
Article
Oceanography
Lina Yang, Xinyang Zhao, Peng Liang, Tianyu Zhang, Lingling Xie, Raghu Murtugudde
Summary: Variations in sea level in the southwest Pacific play an important role in the bifurcation of equatorial currents and the Indonesian Throughflow transport, which are significant for climate variability and change. The study reveals that the first baroclinic mode dominates the sea level variations in the tropics, while higher baroclinic modes affect the extratropics. Seasonally, wind-driven first-mode baroclinic Rossby waves control the sea level variations in most tropical Pacific regions. El Nino-Southern Oscillation (ENSO) is found to be the main contributor to interannual variability. Wind-driven Rossby and Kelvin waves explain a significant portion of interannual variance in the tropical Pacific. In the non-tropical regions, small-scale diffusive processes are believed to be critical for interannual variability.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Oceanography
Lisa Maillard, Julien Boucharel, Lionel Renault
Summary: This study investigates the impact of Tropical Instability Waves (TIWs) on the mean state of the eastern tropical Pacific. The results show that TIWs attenuate the direct effect of heat advection by cooling down the cold tongue, through the modulation of the Equatorial Undercurrent. This research provides insights for better understanding the mean state of the eastern tropical Pacific and the development of TIW parameterizations in Earth system models.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Oceanography
Devanarayana R. M. Rao, Neil F. Tandon
Summary: Recent research indicates that the variability of the Indo-Pacific MOC plays a crucial role in global MOC variability on interannual timescales, with a prominent feature being the cross-equatorial cell (CEC). Through analysis of observational estimates, it is found that anomalies in atmospheric circulation and hydrological cycle lead to equatorially antisymmetric density anomalies, driving the formation of CEC. This contrasts with mechanisms on seasonal timescales, where the Ekman response to zonal wind stress anomalies is primarily responsible for anomalous cross-equatorial overturning.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Oceanography
Ke Huang, Dongxiao Wang, Yun Qiu, Ying Wu, Kexiu Liu, Bohua Huang, Dandan Sui
Summary: This study investigates the latitudinal width variability of near-equatorial zonal currents in the upper Indian Ocean and the underlying causes. The results show that the variability of these currents has both seasonal and interannual differences, and it is influenced by anomalous wind forcing. The near-equatorial zonal currents are asymmetrically responsive to the Indian Ocean Dipole (IOD) and are closely related to changes in ocean temperature.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Environmental Sciences
Masahiro Watanabe, Jean-Louis Dufresne, Yu Kosaka, Thorsten Mauritsen, Hiroaki Tatebe
Summary: The east-west gradient in equatorial Pacific sea surface temperature has strengthened since the mid-twentieth century, but models suggest a weakening of the gradient in past and future climates; internal climate variability may be driving the observed intensifying SST gradient, which is projected to reverse in the future according to models.
NATURE CLIMATE CHANGE
(2021)
Article
Meteorology & Atmospheric Sciences
Hao Wang, Xiao-Tong Zheng
Summary: This study investigates the interdecadal variability of cross-equatorial meridional winds in the eastern Pacific and its correlation with the El Nifio-Southern Oscillation (ENSO). Both observations and CMIP6 models show a negative correlation between interannual variations of the winds and ENSO, synchronized with the interdecadal variability of the winds. However, this relationship is underestimated in the models, especially in the historical simulations.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Ulla K. Heede, Alexey V. Fedorov
Summary: This study examines the discrepancy between recent intensification of the tropical Pacific east-west temperature gradient and climate model predictions of future weakening. Results suggest that increased CO2 may lead to an eastern equatorial Pacific warming pattern as greenhouse gases overcome aerosol forcing.
NATURE CLIMATE CHANGE
(2021)
Article
Meteorology & Atmospheric Sciences
Qiwei Sun, Yan Du
Summary: This study investigates the impact of global warming on sea surface salinity and hydrological cycle in the tropical Atlantic and tropical eastern Pacific. The results show that the global water cycle is enhanced and there is El Nino-like sea surface temperature (SST) warming. Under global warming, the water vapor transport between the tropical Atlantic and Pacific increases, resulting in a decrease in salinity in the tropical Pacific and an increase in the tropical Atlantic. The increase in trans-basin SST gradient leads to the enhancement and westward shift of the Walker Circulation, which further affects precipitation and salinity in the tropical Pacific. Additionally, the El Nino-like SST warming induces a wind-evaporation-SST feedback in the tropical eastern Pacific, impacting precipitation and salinity patterns.
Article
Meteorology & Atmospheric Sciences
Jiyeong Kim, Sarah M. Kang, Shang-Ping Xie, Baoqiang Xiang, Doyeon Kim, Xiao-Tong Zheng, Hai Wang
Summary: This study investigates the effect of ocean dynamics on the tropical climate response to localized radiative cooling over three northern extratropical land regions. The results show that ocean dynamics can modulate the spatial pattern of climate response and its effect depends on the extratropical forcing location.
Article
Meteorology & Atmospheric Sciences
Liu Yang, Shang-Ping Xie, Samuel S. P. Shen, Jing-Wu Liu, Yen-Ting Hwang
Summary: It is found that the interaction between low clouds and sea surface temperature (SST) in the northeastern Pacific Ocean (NEP) leads to positive feedback and amplifies SST variations. Wind fluctuations and surface evaporation contribute to the variability of SST through wind-evaporation-SST (WES) feedback. The study confirmed the mediating role of the NEP low cloud-SST feedback in modulating ENSO.
JOURNAL OF CLIMATE
(2023)
Article
Oceanography
Zhangzhe Zhao, Wei Wu, Minyang Wang, Yan Du
Summary: This study investigated the circulation structure in the western tropical Indian Ocean (WTIO) using surface drifters and Simple Ocean Data Assimilation (SODA). Three distinct seasonally dependent patterns of western boundary currents in the WTIO are observed based on drifter trajectories. The geostrophic and wind-driven components were found to dominate the mean state and seasonal variations of circulation in the WTIO.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Geosciences, Multidisciplinary
Matthew T. Luongo, Shang-Ping Xie, Ian Eisenman, Yen-Ting Hwang, Hung-Yi Tseng
Summary: Previous studies have shown that aerosol-like cooling in the Northern Hemisphere leads to a La Nina-like response in the tropical Indo-Pacific. This study investigates the communication and sustainability of this response through a coupled ocean-atmosphere feedback pathway. The results suggest that the buoyancy-forced response dominates in the subtropics, amplifying sea surface temperature anomalies and communicating wind-driven evaporative cooling to the tropics. In the equatorial Indo-Pacific, buoyancy-forced ocean dynamics cool the surface while the Bjerknes feedback creates zonally asymmetric SST patterns. Robustness of the subtropical low cloud feedback pathway is observed across multiple models.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Chuan-Yang Wang, Xiao-Tong Zheng, Shang-Ping Xie
Summary: This study demonstrates that under global warming, annual variability in precipitation, low-level winds, and sea level pressure over the Indo-western Pacific will intensify. This intensification is primarily attributed to the increased specific humidity, resulting in enhanced precipitation variability. The strengthened large-scale anomalous anticyclone further intensifies the precipitation anomalies. However, the interbasin positive feedback between the anticyclone and northern Indian Ocean SST shows no significant change.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Qihua Peng, Shang -ping Xie, Rui Xin Huang, Weiqiang Wang, Tingting ZU, Dongxiao Wang
Summary: This study reveals that the slowdown of the Indonesian Throughflow (ITF) under anthropogenic warming is mainly caused by remote anomalous buoyancy forcing in the North Atlantic Ocean. Surface freshening and warming in the North Atlantic Ocean slow down the Atlantic meridional overturning circulation (AMOC), leading to a reduction in ITF transport.
JOURNAL OF CLIMATE
(2023)
Article
Oceanography
Xiangpeng Wang, Yan Du, Yuhong Zhang, Tianyu Wang, Minyang Wang, Zhiyou Jinga
Summary: In May 2021, a lens-shaped subsurface anticyclonic eddy was observed in the northern South China Sea between 20 and 200 m. The eddy displayed positive sea level anomaly and negative sea surface temperature anomaly. The evolution of the eddy was influenced by anomalous water properties and seasonal changes in sea surface heat flux.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Geography, Physical
Yunfan Chen, Yan Du, Zesheng Chen
Summary: The Indo-western Pacific Ocean capacitor (IPOC) effect induces climate variations over the Indowestern Pacific Ocean, with significant sea-surface temperature (SST) anomalies over the South China Sea (SCS). Coral records serve as proxies for SST and have proven the existence of IPOC as an intrinsic climate mode in the Indo-western Pacific Ocean.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Environmental Sciences
Yating Ouyang, Yuhong Zhang, Jianwei Chi, Qiwei Sun, Yan Du
Summary: Satellite measurements have greatly improved sea surface salinity (SSS) observations, but deviations still exist compared to in-situ measurements. These deviations are related to environmental factors such as sea surface temperature (SST), precipitation, and wind speed. Deviations are largest in middle and high latitudes, where the SST is colder. Heavy rainfall and strong westerly winds also contribute to larger deviations. In tropical convergence zones, large deviations are mainly caused by heavy rainfall and result in significant freshening. The Level 2 SSS measurements show stronger biases related to rainfall compared to Level 3. Surface freshening is more apparent in low wind speed scenarios.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Yadi Li, Shang-Ping Xie, Tao Lian, Gan Zhang, Juan Feng, Jing Ma, Qihua Peng, Wenzhu Wang, Yurong Hou, Xichen Li
Summary: El Nino triggers variations in the global Hadley circulation, while the latter may potentially feedback to El Nino events. Previous studies mainly focused on the interactions between El Nino and the zonal-mean Hadley circulation. This study introduces a regional perspective by considering zonal variations in the Hadley circulation. The results show intensification of the regional Hadley circulation over the central-eastern Pacific during El Nino, while weakening over the Indo-Pacific warm pool and the tropical Atlantic. The asymmetric component of the Hadley circulation has a lead correlation with El Nino, with the springtime anomaly leading the El Nino event.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Jianwei Chi, Yan Du, Jifeng Qi, Minyang Wang, Ruyan Chen
Summary: Observations of Argo profiles and TAO/TRITON array confirm the seasonal variations of the barrier layer (BL) and temperature inversion (TI) in the northeastern tropical Pacific (NETP). The statistics based on the Argo profiles reveal a bimodal variability of the BL, with peaks in July and October. The bimodal seasonality of BL is attributed to the out-of-phase variations of the eastern Pacific fresh and warm pools. The ITCZ rainfall and northward cold advection from equator dominate the upper layer stratification of NETP in summer and autumn, respectively.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Multidisciplinary Sciences
Ying Zhang, Yan Du, Ming Feng, Alistair J. Hobday
Summary: The study identifies four main types of vertical structures of marine heatwaves using Argo profiles and reveals their spatial distributions. These vertical structures are influenced by ocean dynamical processes and show significant increasing trends in area and depth over the past two decades.
NATURE COMMUNICATIONS
(2023)
Article
Ecology
Udhi E. Hernawan, Kor-jent van Dijk, Gary A. Kendrick, Ming Feng, Oliver Berry, Christopher Kavazos, Kathryn McMahon
Summary: Understanding patterns of gene flow and processes driving genetic differentiation is important for conservation practices. By applying a seascape genetic approach to seagrass populations, this study demonstrates the significant role of oceanographic connectivity and habitat characteristics in shaping spatial genetic structure and gene flow patterns.
ECOLOGY AND EVOLUTION
(2023)
Article
Oceanography
Lingxing Dai, Xingwei Jiang, Yifan Xia, Minyang Wang, Shilin Tang, Yan Du
Summary: This study reports the merging process of the Great Whirl (GW) and the Socotra Gyre (SoG) in the Arabian Sea in September 2019. The merging was first detected at the subsurface layer rather than the surface, and it occurred rapidly at 100-200 m depth. The predominating energy sources for the merged eddy were barotropic and baroclinic instability. The merging process stimulated submesoscale activities and promoted ocean vertical exchanges.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)