Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Michael J. Mcphaden, Congwen Zhu, Yunyun Liu
Summary: This study compares the evolution of atmospheric and oceanic anomalies as well as predictions for the two most recent triple-dip La Niña events in 1998-2001 and 2020-2023. The results show that surface easterly winds were stronger and there was an increased east-west sea surface temperature contrast along the equator during the 2020-2023 event. It is speculated that the mean state change with enhanced zonal sea surface temperature contrast and trade winds over the last several decades influenced the predictability of the most recent La Niña event.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Ting Liu, Xunshu Song, Youmin Tang, Zheqi Shen, Xiaoxiao Tan
Summary: This study conducted a long-term ensemble retrospective prediction using a CGCM, evaluating the contribution of DC and SC to the predictability of ENSO. The results showed that SC is more important, while DC is also significant in short-term and weak signal years. SC dominates the seasonal variation of ENSO predictability, and controls the variability of ENSO predictability at the interdecadal scale.
JOURNAL OF CLIMATE
(2022)
Article
Multidisciplinary Sciences
Nick Dunstone, Doug M. Smith, Steven C. Hardiman, Paul Davies, Sarah Ineson, Shipra Jain, Chris Kent, Gill Martin, Adam A. Scaife
Summary: Skilful predictions of near-term climate extremes are crucial for a resilient society. However, current methods of analysing seasonal forecasts are not effective in identifying rare and impactful extremes. This article argues that a strong summer La Nina provided an opportunity to issue a more confident forecast for extreme rainfall. The authors emphasize the need for improved tools and routine monitoring of forecasts to identify and issue trustworthy early warnings for regional climate extremes.
NATURE COMMUNICATIONS
(2023)
Article
Oceanography
Ting Liu, Youmin Tang, Chunzai Wang, Xunshu Song
Summary: This study investigates the probabilistic predictability of the El Nino-Southern Oscillation (ENSO) using a long-term retrospective forecast from a complicated coupled general circulation model (CGCM). The results suggest that above and below normal events are more predictable than neutral events. The predictability of ENSO shows notable seasonal and interdecadal variation due to the variability of the ENSO signal intensity.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Multidisciplinary Sciences
Fenghua Ling, Jing-Jia Luo, Yue Li, Tao Tang, Lei Bai, Wanli Ouyang, Toshio Yamagata
Summary: This study challenges the long-standing problem of IOD prediction and proposes a multi-task deep learning model called MTL-NET. The model outperforms world-class dynamical models in predicting IOD and correctly captures the non-linear relationships between IOD and predictors.
NATURE COMMUNICATIONS
(2022)
Article
Engineering, Marine
Meiyi Hou, Wansuo Duan, Xiefei Zhi
Summary: The accuracy of ENSO predictions is influenced by initial errors in different key areas of the Pacific Ocean. Assimilation techniques can be used to improve the accuracy by eliminating these errors. However, there have been limited studies on the impact of assimilating ocean temperature data from different regions on ENSO predictions.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Meteorology & Atmospheric Sciences
Ting Liu, Xunshu Song, Youmin Tang
Summary: This study found that the Central-Pacific ENSO has a more obvious Spring Predictability Barrier and lower deterministic prediction skill, while the Eastern-Pacific ENSO has a higher upper limit of prediction skill. The predictability of the two flavors of ENSO shows distinct interdecadal variation but their predictability trends are not synchronized.
Article
Meteorology & Atmospheric Sciences
Stephen J. Vavrus, Fuyao Wang, Paul Block
Summary: This study assessed the accuracy of seven global climate models (GCMs) in predicting rainy season precipitation in coastal Peru. The results showed a wide range in accuracy among the models, with the forecasts generally overestimating the precipitation. The accuracy of the forecasts decreased with increasing lead time and varied across different regions. The study also found that the relationship between rainfall and El Nino-Southern Oscillation (ENSO) influenced the forecast skill.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Antje Weisheimer, Magdalena A. Balmaseda, Tim N. Stockdale, Michael Mayer, S. Sharmila, Harry Hendon, Oscar Alves
Summary: This study explores the temporal changes of predictability of El Nino Southern Oscillation (ENSO) using a modern forecasting system. The results reveal distinct periods of enhanced and reduced predictability, primarily driven by multi-decadal variations in the dynamical characteristics of ENSO.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
P. Rohini, M. Rajeevan, Suryachandra A. Rao, Prasanth A. Pillai
Summary: This study evaluates the skill of seasonal forecasts of temperatures over India during April to June using the Monsoon Mission Coupled Forecasting System (MMCFS) model hindcasts. The results show that the model has a significant skill for seasonal forecasts of temperatures over most of northwest and central India. Additionally, the model is capable of predicting the spatial distribution of heat wave characteristics reasonably well.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Yingying Zhao, Yishuai Jin, Jianping Li, Antonietta Capotondi
Summary: This study investigates the impacts of extratropical Pacific on the El Nino-Southern Oscillation (ENSO) spring predictability barrier (SPB). The results show that the northern and southern extratropical Pacific can equally weaken the Eastern Pacific-ENSO SPB, while the North Pacific is more important for weakening the Central Pacific-ENSO SPB. Additionally, the study demonstrates the decisive role of the South Pacific initial condition in ENSO diversity.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Marine
Peter Rogowski, Sophia Merrifield, Clarence Collins, Tyler Hesser, Allison Ho, Randy Bucciarelli, James Behrens, Eric Terrill
Summary: Landfalling tropical cyclones generate extreme waves, posing significant risks and damage. Accurate simulations of sea state during these storms are crucial but challenging. Studies show a general tendency for wave models to underestimate significant wave height, with distinct error patterns on an individual cyclone basis.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Environmental Sciences
Ran Wang, Lin Chen, Tim Li, Jing-Jia Luo
Summary: The prediction skill of Atlantic Nino/Nina has been improved, with the multi-model ensemble reaching five months, but it is season-dependent, showing a marked decrease in spring prediction ability.
Article
Meteorology & Atmospheric Sciences
Jing Ma, Shang-Ping Xie, Haiming Xu, Jiuwei Zhao, Leying Zhang
Summary: Utilizing the ensemble hindcasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) coupled model, this study investigates the spatiotemporal evolution of sea surface temperature (SST) and low-level winds in the tropical Atlantic, revealing the influence of North Tropical Atlantic (NTA) SST anomalies on the development of El Nino-Southern Oscillation (ENSO) events. The results show a pathway for the delayed effect of NTA SST anomalies on subsequent ENSO events and demonstrate the role of NTA SST warming in setting off a North Pacific meridional mode (NPMM), ultimately leading to La Nina events.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Tong Zhang, Haiming Xu, Jing Ma, Jiechun Deng
Summary: This study investigates the predictability of marine heatwaves in the Northwest Pacific during summer. The research demonstrates that the spatial pattern of total marine heatwave days can be predicted up to eight months in advance. Furthermore, the linear trend and interannual variability can be predicted up to nine and three months in advance, respectively.
WEATHER AND CLIMATE EXTREMES
(2023)
Article
Meteorology & Atmospheric Sciences
Yunyun Liu, Zeng-Zhen Hu, Renguang Wu, Bhaskar Jha, Qiaoping Li, Lijuan Chen, Jinghui Yan
Summary: The study examines the subseasonal prediction skills and biases of summer rainfall over eastern China in the Beijing Climate Center (BCC) Atmospheric General Circulation Model (BCC_AGCM2.2), finding that the model shows some skill in predicting summer rainfall within certain lead-times but overall has low subseasonal prediction skill due to biases in the model. Additionally, the Pacific-Japan pattern is not well predicted for both its spatial pattern and subseasonal evolution.
Article
Meteorology & Atmospheric Sciences
Zeng-Zhen Hu, Arun Kumar, Jieshun Zhu
Summary: Spatial patterns of signal and noise components for sea surface temperature (SST) predictions have not been analyzed in contrast to the temporal evolution of forecast ensemble mean (signal) and spread (noise) in an ensemble of seasonal forecasts. It is found that the leading empirical orthogonal function pattern of SST is similar between the signal and the noise with maximum loading in the central and eastern tropical Pacific associated with El Nino-Southern Oscillation (ENSO) variability. Although the largest variability in the signal and the noise is spatially collocated, their temporal evolution is independent.
Article
Meteorology & Atmospheric Sciences
Lei Zhang, Weiqing Han, Zeng-Zhen Hu
Summary: In 2019, an unprecedented extreme positive Indian Ocean dipole event occurred, leading to disastrous impacts on countries bordering the Indian Ocean. Various factors, including easterly wind bursts, warm sea surface temperature anomalies in the central-western tropical Pacific Ocean, and Madden-Julian oscillation events played key roles in triggering and sustaining the extreme pIOD.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Yihui Ding, Yunyun Liu, Zeng-Zhen Hu
Summary: The record-breaking meiyu season in the Yangtze-Huaihe River valley in 2020 was characterized by long duration, abundant precipitation, and frequent heavy rainstorm processes, closely associated with a significant quasi-biweekly oscillation in the East Asian monsoon circulation system.
ADVANCES IN ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Bohua Huang, Cristiana Stan
Summary: The study investigates the predictability of land climate at seasonal and interannual time scales, attributing it largely to the influence of the ocean. Connections between global sea surface temperature anomaly (SSTA) and land precipitation anomaly are examined using observations and Atmospheric Model Intercomparison Project (AMIP) simulations for the period 1957-2018. The results show that SSTA in the tropical central and eastern Pacific has strong connections with global land precipitation anomaly, with weaker connections observed in the equatorial Indian and Atlantic Oceans.
Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Bohua Huang, Fei-Fei Jin
Summary: This study investigates the connection between meridional transport convergences (MTCs) along the equatorial Pacific and variations in warm water volume, as well as their relationship with the El Nino-Southern Oscillation (ENSO) cycle. The results show that the Sverdrup MTC induced by wind stress curl has a significant impact on the thermocline fluctuation in the equatorial Pacific, with varying contributions from different components. The findings enhance our understanding and forecasting of ENSO evolution.
Article
Geosciences, Multidisciplinary
Zhensong Gong, Yunyun Liu, Zeng-Zhen Hu, Ping Liang
Summary: In the summer of 2020, there was a significant transition in tropical cyclone activities over the western North Pacific. The variation in mid-tropospheric relative humidity and upward convective motion was found to be the main factor for this transition, while sea surface temperature, low-level vorticity, and vertical wind shear anomalies played a secondary role. The abnormal variation in monsoon activity also had an impact on the meteorological conditions.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Meteorology & Atmospheric Sciences
Yunyun Liu, Zeng-Zhen Hu, Renguang Wu, Xing Yuan
Summary: In the spring of 2021, southwestern China experienced extreme drought and high temperatures. Unlike historical events, this drought was mainly caused by atmospheric internal variability and amplified by climate warming trends, rather than El Nino. Evaporation increase accounted for 30% of the drought severity, with 20% contributed by its linear trend and 10% by interannual variability. The sea surface temperature forcing played a minor role in the occurrence of drought, making it difficult for climate models to predict the 2021 drought in southwestern China beyond one-month lead times.
ADVANCES IN ATMOSPHERIC SCIENCES
(2022)
Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Zhiqiang Gong, Bhaskar Jha
Summary: This study quantitatively assesses the impact of global sea surface temperature anomalies (SSTAs) on land precipitation anomalies using a new metric, and compares observations with model simulations. The results show that SSTAs have different effects on precipitation variations in different regions, with hotspot areas identified in the Sahel region, Indochina Peninsula, and southwestern United States. The simulations underestimate the influence of SSTAs on land precipitation, but ensemble means amplify the integrated impact.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Yu-heng Tseng, Yunyun Liu, Ping Liang
Summary: This study examines the evolution and impact of the 2020/2021 La Nina event and compares it with historical events. It found that the La Nina event during this period was weaker than expected and showed some differences compared to other events, indicating that the in-phase amplification of time scale variations is an important factor determining the intensity of La Nina events.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Editorial Material
Meteorology & Atmospheric Sciences
Xianghui Fang, Fei Zheng, Kexin Li, Zeng-Zhen Hu, Hongli Ren, Jie Wu, Xingrong Chen, Weiren Lan, Yuan Yuan, Licheng Feng, Qifa Cai, Jiang Zhu
Summary: Based on the latest climate predictions, it is expected that El Nino will continue into the summer and fall, leading to a possible three-year La Nina event. This would be the first three-year La Nina event since 1998-2001, and it could have significant global climate impacts.
ADVANCES IN ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Zongting Gao, Zeng-Zhen Hu, Fei Zheng, Xiaofan Li, Shangfeng Li, Banglin Zhang
Summary: This study demonstrates the diversity of single- and double-year El Nino events in their strengths, flavors, as well as associations with the recharge/discharge processes. Both types occur in the central and eastern Pacific, with double-year El Nino showing unique characteristics in warm water volume.
Article
Geosciences, Multidisciplinary
Xiaofan Li, Zeng-Zhen Hu, Sen Zhao, Ruiqiang Ding, Banglin Zhang
Summary: The El Nino/Southern Oscillation (ENSO) plays a crucial role in successful climate prediction at seasonal-interannual time scales. Differences in intensities and spatial patterns associated with preceding thermocline fluctuation in the equatorial Pacific during the recharge and discharge phases of ENSO can be attributed to asymmetric wind stress anomalies related to El Nino and La Nina.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Ruiqiang Ding, Yu-Heng Tseng, Emanuele Di Lorenzo, Liang Shi, Jianping Li, Jin-Yi Yu, Chunzai Wang, Cheng Sun, Jing-Jia Luo, Kyung-Ja Ha, Zeng-Zhen Hu, Feifei Li
Summary: The authors find that persistent two-way teleconnections between the North Pacific Oscillation and the tropical Pacific are a key source of multi-year El Nino events. These teleconnections lead to the prolonged El Nino phenomena, resulting in severe floods and droughts worldwide with significant socioeconomic impacts. Model experiments and future projections suggest that with enhanced NPO variability under future anthropogenic forcing, more frequent multi-year El Nino events should be expected. Therefore, properly accounting for the effects of the NPO on the evolution of El Nino events may improve multi-year El Nino prediction and projection.
NATURE COMMUNICATIONS
(2022)
Article
Meteorology & Atmospheric Sciences
Yunyun Liu, Zeng-Zhen Hu, Renguang Wu, Yihui Ding, Bhaskar Jha
Summary: The El Nino-Southern Oscillation (ENSO) has complex and controversial impacts on East Asian precipitation. In the past two decades, the ENSO impact on precipitation has weakened or strengthened depending on the phase. The distribution of East Asian precipitation anomalies is asymmetric in El Nino and La Nina years. Model simulations confirm the robust impact of ENSO on East Asian climate.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2023)