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Impacts of the annual cycle of background sst in the tropical Pacific on the phase and amplitude of ENSO

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 12-17页

作者： Song Jiang Congwen Zhu Ning Jiang State Key Laboratory of Severe Weather(LASW) Chinese Academy of Meteorological SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina

The dominant annual cycle of sea surface temperature(sst)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of *** on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual *** magnitude of the sst anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity *** reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background sst on ENSO,which possibly carries important implications for forecasting ENSO.

关键词： Annual cycle sst anomaly Antisymmetric mode ENSO

Detecting Primary Precursors of January Surface Air Temperature Anomalies in China

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Journal of Meteorological Research 2017年第6期31卷 1096-1108页

作者： Guirong TAN Hong-Li REN Haishan CHEN Qinglong YOU Key Laboratory of Meteorological Disaster of Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science &Technology Laboratory for Climate Studies/CMA–NJU Joint Laboratory for Climate Prediction Studies National Climate CenterChina Meteorological Administration Department of Atmospheric Science School of Environmental Studies China University of Geoscience

This study aims to detect the primary precursors and impact mechanisms for January surface temperature anomaly （JSTA） events in China against the background of global warming, by comparing the causes of two extreme JSTA events occurring in 2008 and 2011 with the common mechanisms inferred from all typical episodes during 1979- 2008. The results show that these two extreme events exhibit atmospheric circulation patterns in the mid-high latitudes of Eurasia, with a positive anomaly center over the Ural Mountains and a negative one to the south of Lake Baikal （UMLB）, which is a pattern quite similar to that for all the typical events. However, the Eurasian teleconnection patterns in the 2011 event, which are accompanied by a negative phase of the North Atlantic Oscillation, are different to those of the typical events and the 2008 event. We further find that a common anomalous signal appearing in early summer over the tropical Indian Ocean may be responsible for the following late-winter Eurasian teleeonnec- lions and the associated JSTA events in China. We show that sea surface temperature anomalies （sstAs） in the preceding summer over the western Indian Ocean （WIO） are intimately related to the UMLB-like circulation pattern in the following January. Positive WIOsstAs in early summer tend to induce strong UMLB-like circulation anomalies in January, which may result in anomalously or extremely cold events in China, which can also be successfully reproduced in model experiments. Our results suggest that the WIOsstAs may be a useful precursor for predicting JSTA events in China.

关键词： Eurasian teleconnection anomalous temperature in China seasonal climate prediction sst anomaly western Indian Ocean model experiment

The 2016 Summer Floods in China and Associated Physical Mechanisms:A Comparison with 1998

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Journal of Meteorological Research 2017年第2期31卷 261-277页

作者： Yuan YUAN Hui GAO Weijing LI Yanju LIU Lijuan CHEN Bin ZHOU Yihui DING Laboratory for Climate Studies National Climate CenterChina Meteorological Administration Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science &Technology

The characteristics of droughts and floods in China during the summers（May–August）of 2016 and 1998 were compared in great detail,together with the associated atmospheric circulations and external-forcing *** results are obtained.（1）The precipitation was mostly above normal in China in summer 2016,with two main rainfall belts located in the Yangtze River valley（YRV）and North *** with 1998,a similar rainfall belt was located over the YRV,with precipitation 100%and more above ***,the seasonal processes of Meiyu were different.A typical＂Secondary Meiyu＂occurred in 1998,whereas dry conditions dominated the YRV in2016.（2）During May–July 2016,the Ural high was weaker than normal,but it was stronger than normal in *** difference resulted from fairly different distributions of sea surface temperature anomalies（sstAs）over the North Atlantic Ocean during the preceding winter and spring of the two years.（3）Nonetheless,tropical and subtropical circulation systems were much more similar in May–July of 2016 and *** circulation systems in both years were characterized by a stronger than normal and more westward-extending western Pacific subtropical high（WPSH）,a weaker than normal East Asian summer monsoon（EASM）,and anomalous convergence of moisture flux in the mid and lower reaches of the *** similar circulation anomalies were attributed to the similar tropical sstA pattern in the preceding seasons,i.e.,the super El Ni？o and strong warming in the tropical Indian Ocean.（4）Significant differences in the circulation pattern were observed in August between the two *** WPSH broke up in August 2016,with its western part being combined with the continental high and persistently dominating eastern *** EASM suddenly became stronger,and dry conditions prevailed in the *** the contrary,the EASM was weaker in August 1998 and the＂Secondary Meiyu＂took place in the *** Madden–Julian Oscillation（MJO）was extremely active in Aug

关键词： summer precipitation flooding Yangtze River valley super El Ni?o sst anomaly tropical Indian Ocean snow cover over the Qinghai–Tibetan Plateau Madden–Julian Oscillation

SPATIO-TEMPORAL VARIATION OF SEASONAL EXTREME WET DAYS IN CHINA AND ITS RELATIONSHIP WITH sst ANOMALIES

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Journal of Tropical Meteorology 2012年第4期18卷 485-493页

作者：汪卫平杨修群谢益军邹用昌房佳蓓谢倩 Institute for Climate and Global Change Research School of Atmospheric SciencesNanjing University Hunan Meteorological Bureau Institute of Meteorology PLA University of Science and Technology

With daily precipitation records at 586 stations in China for 1960-2004, this study investigates the spatio-temporal variation of the number of extreme wet days (NEWD) for each season in China and its relationship with sst anomalies and associated atmospheric circulation anomaly patterns, in which a threshold of extreme precipitation for a season and a station is defined as the value of the 90th percentile when the precipitation records for wet days during the season are ranked in an increasing order. Results show that there are significant increases of the NEWD along the Yangtze River valley during winter and summer, in North China during winter, in South China during spring, in Northeast China during winter and spring, and in Northwest China throughout the seasons, while there is a remarkable decrease in North China during summer. Besides the linear trend, the NEWD also exhibits considerable interannual and interdecadal variabilities. After eliminating the linear trend, the NEWD anomalies show distinct seasonal patterns. The NEWD anomalies are characterized by a "dipole" mode with opposite phases between northern and southern China in spring and autumn, a "tri-pole" mode with opposite phases between Yangtze River valley and southern and northern China in summer, and a "monopole" mode with the same phase over most of China in winter. The relationship of the NEWD anomalies in China with the sst anomalies in Indian and Pacific Oceans is found to be mainly dependent on the ENSO, and associated atmospheric circulation anomaly patterns for the ENSO's impact on the NEWD in China are identified.

关键词： extreme precipitation number of extreme wet days sst anomaly ENSO

Model　Study　on　the　Interannual　Variability　of　Asian　Winter　Monsoon　and　Its　Influence

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Advances in Atmospheric Sciences 1997年第1期14卷 2-14,16-23页

作者：纪立人孙淑清 Institute of Atmospheric Physics Chinese Academy of Sciences Beijing Max-Plank Institute for Meteorology Hamburg Germany

The interannual variation of Asian winter (NE) monsoon and its influence is studied using the long-term integration of Max-Plank Institute ECHAM3(T42 L19) model. The simulation well reproduces the main features of the climatological mean Asian winter monsoon and shows pronounced difference of atmospheric circulation between strong and weak winter monsoon and for the consecutive seasons to follow. Most striking is the appearance and persistence of an anomalous cyclonic flow over the western Pacific and enhanced Walker circulation for strong winter monsoon in agreement with the observation. The contrast in summer rainfall patterns of both East China and India can also be discerned in the simulation. Comparison of three sets of experiments with different sst shows that the forcing from the anomalies of global sst makes a major contribution to the interannual variability of Asiao winter monsoon and, in particular, to the interseasonal persistence of the salient features of circulation. The sstA over the tropical western Pacific also plays an important part of its own in modulating the Walker circulation and the extratropical flow patterns. The apparent effect of strong NE monsoon is to enhance the convection over the tropical western Pacific. This effect, on the one hand, leads to a strengthening of SE trades to the east and extra westerly flow to the west, thus favorable to maintaining a specific pattern of sstA. On the other hand, the thermal forcing associated with the sstA acts to strengthen the extratropical flow pattern which is, in turn, conducive to stronger monsoon activity. The result seems to suggest a certain self-sustained regime in the air-sea system, which is characterized by two related interactions, namely the air-sea and tropical-extratropical interactions with intermittent outburst of NE cold surge as linkage. There is a connection between the strength of the Asian winter monsoon and the precipitation over China in the following summer. Links b

关键词： Winter monsoon Interannual variability,Interseasonal connection sst anomaly

Analysis of rainfall variability over Tanzania in late austral summer

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Atmospheric and Oceanic Science Letters 2021年第4期14卷 13-18页

作者： Witness Clay Massawe Ziniu Xiao State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina

Based on site-observation data,NCEP–NCAR reanalysis data,and Climatic Research Unit gridded data,the rainfall variability over Tanzania during late austral summer(January–March,JFM)was analyzed for the period 1961–***,the associated atmospheric circulation and sst anomalies(sstAs)were explored to understand the mechanisms of dry-and wet-year cases based on an interannual time *** correlation,Morlet wavelet power spectrum,and composite analysis methods were *** results showed that the JFM standardized rainfall anomaly time series exhibited significant time scales of variability at interannual(2–8 years)and quasidecadal(8–12 years).During dry years,anomalous anticyclonic northeasterly flow originating from western tropical Indian and southeast trades from the Indian Ocean to the southeast were associated with subsiding dry air,which resulted in suppression of rainfall as *** the typical wet-year cases,meanwhile,anomalous westerlies from the tropical and southeast Atlantic were strengthened over the Congo basin,delivering more precipitation to the *** correlation was exhibited over the western tropical and southeast Indian Ocean,as well as the southeast and tropical Atlantic *** sstA patterns favored atmospheric general circulation anomalies that were closely related to JFM rainfall over Tanzania.

关键词： Rainfall variability Tanzania sst anomaly Dry and wet year Atmospheric general circulation

Numerical Simulation of the Effect of the sst Anomalies in the Tropical Western Pacific on the Blocking Highs over the Northeastern Asia

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Advances in Atmospheric Sciences 1996年第4期13卷 411-424页

作者：陆日宇黄荣辉 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100080

The effects of the sea surface temperature (sst) anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are simulated by the IAP-GCM with an observed and idealized distributions of the sst anomalies in the tropical western Pacific,***,the atmospheric circulation anomalies during July and August,1980 are simulated by three anomalous experiments including the global sst anomaly experiment,the tropical sst anomaly experiment and the extratropical sst anomaly experiment,using the observed sst anomalies in *** is shown that the sst anomalies in the tropical ocean greatly influence the formation and maintenance of the blocking high over the northeastern Asia,and may play a more important role than the sst anomalies in the extratropical ocean in the influence on the atmospheric circulation ***,the effects of the sst anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are also simulated with an idealized distribution of the sst anomalies in the tropical western *** simulated results show that the negative anomalies of sst in the tropical western Pacific have a significant effect on the formation and maintenance of the blocking high over the northeastern Asia.

关键词： Blocking high sst anomaly Atmospheric circulation anomaly

Interannual and Decadal Variability of the North Pacific Blocking and Its Relationship to sst, Teleconnection and Storm Tracks

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Advances in Atmospheric Sciences 2002年第5期19卷 807-820页

作者：黄菲周发琇钱筱丹 Department of Marine Meteorology Ocean University of Qingdao Qingdao

Climalological features of mid-latitude blocking occurring over the North Pacific Ocean during 52 winters (December to February) of 1948/1949-1999/2000 are statistically analyzed based on NCEP/ NCAR reanalysis data. Significant interannual variation with a period of about 3-7 years as well as decadal variability is found by wavelet analysis and power spectrum analysis. A decreasing trend of the 2-7 year bandscale-averaged variance occurs throughout the 52 years and an abrupt shift from a higher state to a lower state during the 1970s is also found, which suggests an interdecadal variation of the North Pacific blocking. The possible relationship between the variability of blocking and sea surface temperature (sst), storm tracks and teleconnection are shown using composite analysis. In strong blocking anomaly winter (SBW), the geopotential height anomaly at 500 hPa exhibits a typical PNA (Pacific-North American)-like wave-train pattern in the North Pacific. The storm tracks, representing the activity of transient eddies, extend northeastward to the western coast of North America along the mid latitudes of about 40°-50°N, with the sst anomaly exhibiting a Pacific decadal oscillation (PDO) mode at mid-latitude and a La Niña-like pattern along the equator. Contrasting features appear in weak blocking anomaly winter (WBW).

关键词： north Pacific blocking teleconnection sst anomaly storm tracks

A STUDY ON THE RELATIONSHIP BETWEEN THE SUMMER PRECIPITATION IN NORTHEAST CHINA AND THE GLOBAL SEA SURFACE TEMPERATURE anomaly (sstA) IN PRECEDING SEASONS

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Journal of Tropical Meteorology 2004年第1期10卷 43-52页

作者：孙力沈柏竹安刚唐晓玲 Institute of Meteorological Science of Jilin Province Changchun 130062 China

Based on the NCEP/NCAR reanalysis global sst, 500-hPa geopotential height, 850-hPa wind monthly mean data and summer precipitation from 80 observation stations of Northeast China for the period 1961-2000, the summer precipitation field of Northeast China was decomposed by using the principal component analysis method, then the relationships between the first three precipitation leading modes and the global sstA in preceding seasons were studied, and the responses of the 500-hPa atmospheric circulation in East Asia to the preceding winter sstA in north Pacific and its influence on the summer precipitation in Northeast China were probed. The results show that the sstA, especially the ENSO event in preceding seasons has really very important influence on the occurrence of the whole coincident precipitation episode in Northeast China, and relates to the precipitation episodes of the reverse variation in south-north and in west-east direction closely. The north Pacific sst anomalies in preceding winters are associated with the summer precipitation in Northeast China through its influence on the western Pacific subtropical high and the East Asia subtropical monsoon in summer. Therefore, taking the global sstA distribution in preceding seasons, especially the ENSO event, as the precursor signal to predict the precipitation anomaly in Northeast China has good reliability and definite indicative significance.

关键词： summer precipitation in northeast China sst anomaly subtropical high climate prediction