Observational evidence is presented to show a teleconnection between the central Pacific and East Asia during extreme phases of ENSO cycles. This Pacific–East Asian confined lower troposphere. The key system that bridges warm (cold) events in eastern weak (strong) winter monsoons an anomalous lower-tropospheric anticyclone (cyclone) located western North Pacific. wind anomalies develop rapidly late fall year when strong or cold event matures. persist until following spring early summer,...

To date, the monsoon-research community has not yet reached a consensus on unified definition of monsoon rainy season or linkage between onsets over Asian continent and adjacent oceans. A single rainfall parameter is proposed, suite universal criteria for defining domain, onset, peak, withdrawal are developed. These results reveal cohesive spatial–temporal structure Asian–Pacific characteristics, which will facilitate validation hydrological cycles simulated by climate system models improve...

Abstract Analysis of the 56-yr NCEP–NCAR reanalysis data reveals a recurrent circumglobal teleconnection (CGT) pattern in summertime midlatitude circulation Northern Hemisphere. This represents second leading empirical orthogonal function interannual variability upper-tropospheric circulation. The CGT, having zonal wavenumber-5 structure, is primarily positioned within waveguide that associated with westerly jet stream. spatial phases CGT tend to lock preferred longitudes. geographically...

Analyses of 50-yr NCEP–NCAR reanalysis data reveal remarkably different interannual variability between the Indian summer monsoon (ISM) and western North Pacific (WNPSM) in their temporal–spatial structures, relationships to El Niño, teleconnections with midlatitude circulations. Thus, two circulation indices are necessary, which measure ISM WNPSM, respectively. A weak WNPSM features suppressed convection along 10°–20°N enhanced rainfall mei-yu/baiu front. So index also provides a for east...

An analysis of 35-yr (1965–99) data reveals vital impacts strong (but not moderate) El Niño and La Niña events on tropical storm (TS) activity over the western North Pacific (WNP). Although total number TSs formed in entire WNP does vary significantly from year to year, during summer fall, frequency TS formation increases remarkably southeast quadrant (0°–17°N, 140°E–180°) decreases northwest (17°–30°N, 120°–140°E). The July–September mean location is 6° latitude lower, while that...

In the south Asian region, two of major precipitation maxima associated with areas intensive convective activity are located near Bay Bengal and in vicinity Philippines. The variations monthly mean outgoing longwave radiation regions poorly correlated, particularly decade 1980s. enhanced convection over Indian subcontinents is coupled reinforced monsoon circulation west 80°E India, western Ocean, tropical northern Africa. contrast, Philippines corresponds to intensified primarily east...

Asian–Australian monsoon (A–AM) anomalies depend strongly on phases of El Niño (La Niña). Based this distinctive feature, a method extended singular value decomposition analysis was developed to analyze the changing characteristics A–AM during Niña) from its development decay. Two off-equatorial surface anticyclones dominate an Niño—one over south Indian Ocean (SIO) and other western North Pacific (WNP). The SIO anticyclone, which affects climate conditions Ocean, eastern Africa, India,...

Observational evidence presented here indicates that the surface temperatures on Tibetan Plateau (TP) have increased by about 1.8°C over past 50 years. The precipitation pattern is projected as a result of this warming resembles leading variations in East Asia (EA). Numerical experiments with atmospheric general circulation models show heating induced rising TP can enhance Asian subtropical frontal rainfall. mechanism linkage found to be through two distinct Rossby wave trains and isentropic...

The scientific basis for two‐tier climate prediction lies in the predictability determined by ocean and land surface conditions. Here we show that state‐of‐the‐art atmospheric general circulation models (AGCMs), when forced observed sea temperature (SST), are unable to simulate properly Asian‐Pacific summer monsoon rainfall. All yield positive SST‐rainfall correlations at odds with observations. lag between SST rainfall suggest treating as a slave possibly results models' failure. We...

Abstract Defining the intensity of East Asian summer monsoon (EASM) has been extremely controversial. This paper elaborates on meanings 25 existing EASM indices in terms two observed major modes interannual variation precipitation and circulation anomalies for 1979–2006 period. The can be classified into five categories: east–west thermal contrast, north–south shear vorticity zonal winds, southwesterly monsoon, South China Sea monsoon. last four types reflect various aspects leading mode...

Monsoon rainfall and tropical storms (TSs) impose great impacts on society, yet their seasonal predictions are far from successful. The western Pacific Subtropical High (WPSH) is a prime circulation system affecting East Asian summer monsoon (EASM) North TS activities, but the sources of its variability predictability have not been established. Here we show that WPSH variation faithfully represents fluctuations EASM strength (r = -0.92), total days over subtropical -0.81), number TSs...

The spatial and temporal structures of the northward-propagating boreal summer intraseasonal oscillation (BSISO) are revealed based on analysis both ECHAM4 model simulation NCEP–NCAR reanalysis. BSISO structure evolution characteristics simulated by bear many similarities to those derived from most notable features remarkable meridional asymmetries, relative convection, in vorticity specific humidity fields. A positive perturbation with an equivalent barotropic appears a few latitude degrees...

The characteristics of the onset Pacific basin-wide warming have experienced notable changes since late 1970s. are caused by a concurrent change in background state on which El Niño evolves. For most significant warm episodes before 1970s (1957, 1965, and 1972), atmospheric anomalies phase (November to December year preceding Niño) were characterized giant anomalous cyclone over east Australia whose eastward movement brought westerlies into western equatorial Pacific, causing development...

How to predict the year‐to‐year variation of east Asian summer monsoon (EASM) is one most challenging and important tasks in climate prediction. It has been recognized that EASM variations are intimately but not exclusively linked development decay El Niño or La Niña. Here we present observed evidence numerical experiment results show anomalous North Atlantic Oscillation (NAO) spring (April–May) can induce a tripole sea surface temperature pattern persists into ensuing excite downstream...

The tropical intraseasonal oscillation (ISO) exhibits pronounced seasonality. boreal summer ISO is more complex than its winter counterpart due to the coexistence of equatorial eastward, off-equatorial westward, and northward propagating, low-frequency modes their interactions. Based on observational evidence results obtained from numerical experiments, a mechanism proposed for in which Northern Hemisphere monsoon (NHSM) circulation moist static energy distribution play essential roles. With...

The boreal summer intraseasonal oscillation (BSISO) of the Asian monsoon (ASM) is one most prominent sources short-term climate variability in global system. Compared with related Madden-Julian Oscillation (MJO) it more complex nature, northward propagation and extending much further from equator. In order to facilitate detection, monitoring prediction BSISO we suggest two real-time indices: BSISO1 BSISO2, based on multivariate empirical orthogonal function (MV-EOF) analysis daily anomalies...

This study investigates future changes of Global Monsoon (GM) under anthropogenic global warming using 20 coupled models that participated in the phase five Coupled Model Intercomparison Project (CMIP5) by comparing two runs: historical run for 1850–2005 and Representative Concentration Pathway (RCP) 4.5 2006–2100. A metrics evaluation models' performance on GM is designed to document 1980–2005 best four are selected. The multi-model ensemble (B4MME) projects following twenty-first century...

The anomalous Philippine Sea anticyclone (PSAC) conveys impacts of El Niño to east Asian climate during the mature and decay an (from winter ensuing summer). It is shown that PSAC forms in fall about one season prior peak Niño; its strength increases with intensity sign reverses a La Niña. formation concurs abnormal deepening trough increasing number northward recurvature tropical storms western Pacific. establishment abrupt, coupling swing from wet dry phase intraseasonal oscillation (ISO)...

In the late 1970s, ENSO cycle exhibited frequency change. The oscillation period increased from 2–4 yr (high frequency) during 1962–75 to 4–6 (low 1980–93. Observations suggest that this change was accompanied by a significant in structure of coupled mode. comparison with high-frequency regime, mode low-frequency regime shows three distinctive features warm phase ENSO: eastward shift westerly anomalies, meridional expansion and weaker intensity easterly anomalies eastern Pacific. To test...

The global monsoon (GM) is a defining feature of the annual variation Earth's climate system. Quantifying and understanding present-day precipitation change are crucial for prediction its future reflection past. Here we show that regional monsoons coordinated not only by external solar forcing but also internal feedback processes such as El Niño-Southern Oscillation (ENSO). From one year (May to next April) next, most continental regions, separated vast areas arid trade winds deserts, vary...

Four fundamental differences of air–sea interactions between the tropical Pacific and Indian Oceans are identified based on observational analyses physical reasoning. The first difference is represented by strong contrast a zonal cloud–SST phase relationship warm cool oceans. in-phase in oceans leads to negative feedback, while significant cold tongue much weaker thermodynamic damping. second arises from reversal basic-state wind tilting ocean thermocline, which distinctive effects waves....