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1.
The structure of the monsoon depression and the observed flow features prior to and at the time of monsoon depression formation
(composite of 15 depressions) are examined. The composite monsoon depression (transient eddy) has a scale of 25° longitude
and extends up to 300 mb and has the greatest intensity at 700 mb. It shows north-north-east to south-south-west tilt in the
lower levels indicating that it may draw upon zonal kinetic energy for its growth. The disturbance has lower temperatures
to its west and tilts westwards with height indicating that eddy available potential energy is not converted from zonal available
potential energy by large scale advection. There appears to be a reduction of vertical shear at the time of formation of monsoon
depressions and this possibly aids cumulus convection.
The profiles of potential vorticity indicate extremes (i) in the upper troposphere and (ii) at several midtropospheric levels
in the region of the monsoon trough indicating the possibility of combined barotropic-baroclinic instability. Using multi-level
quasi-geostrophic model and employing the eigen-value technique it is shown that the monsoon zonal current is notbaroclinically unstable. A barotropic stability analysis is also done for monsoon zonal current in the lower and middle tropospheres. It
yields very slowly growing unstable modes at lower tropospheric levels with wave lengths of 2500 km and 5000 km. 相似文献
2.
V. Krishnakumar R. N. Keshavamurty S. V. Kasture 《Journal of Earth System Science》1992,101(2):123-152
The objective of this study was two-fold: the first to investigate the role of moist convection and nongeostrophic effects
on the growth of the monsoon depressions using a linearized multi-level moist primitive equation (PE) model and quasi-geostrophic
(QG) model with only vertical shear. The second was to study the nonlinear evolution, growth, movement and detailed energetics
of the monsoon depressions using a nonlinear moist global spectral model.
Our linear studies using both models revealed lower as well as upper tropospheric growing modes. For the lower tropospheric
modes the shorter scales were found to grow faster. While the PE model showed faster growth rate for shorter scales, as compared
to longer scales, the QG model showed less tendency for scale selection. The shorter scales in PE model had phase speeds ranging
from 4 to — 1 ms−1 and in QG model from 8 to — 4 ms−1. The nongeostrophic effects were found to be, in general, important.
One of the lower tropospheric modes with wavelength 2500 km was found to have many features similar to the observed monsoon
depression of the Bay of Bengal.
In the upper troposphere the PE model showed much faster growth rates compared to the QG model. Also the fastest growing mode
with a doubling time of 2.5 days had a scale of 6000 km. This was shorter than the scale predicted in the QG model. This mode
had many characteristics similar to the observed features of the monsoon upper tropospheric easterly waves.
Using a nonlinear global spectral model, we simulated the monsoon depression around 21°N starting from an antisymmetric heating
distribution (with respect to the equator) and with a specific vertical structure with and without basic flows. The model
was integrated for a period of five days incorporating a simple form of cumulus heating. The simulated model disturbance showed
a pronounced growth and a westward movement in the presence of cumulus heating. The detailed energetics calculations revealed
that the baroclinic energy exchange is the primary energy exchange process and cumulus heating is the driving force for the
generation of available potential energy. 相似文献
3.
Holocene climate and cultural evolution in late prehistoric-early historic West Asia 总被引：2，自引：0，他引：2
The precipitation climatology and the underlying climate mechanisms of the eastern Mediterranean, West Asia, and the Indian subcontinent are reviewed, with emphasis on upper and middle tropospheric flow in the subtropics and its steering of precipitation. Holocene climate change of the region is summarized from proxy records. The Indian monsoon weakened during the Holocene over its northernmost region, the Ganges and Indus catchments and the western Arabian Sea. Southern regions, the Indian Peninsula, do not show a reduction, but an increase of summer monsoon rain across the Holocene. The long-term trend towards drier conditions in the eastern Mediterranean can be linked to a regionally complex monsoon evolution. Abrupt climate change events, such as the widespread droughts around 8200, 5200 and 4200 cal yr BP, are suggested to be the result of altered subtropical upper-level flow over the eastern Mediterranean and Asia.The abrupt climate change events of the Holocene radically altered precipitation, fundamental for cereal agriculture, across the expanse of late prehistoric-early historic cultures known from the archaeological record in these regions. Social adaptations to reduced agro-production, in both dry-farming and irrigation agriculture regions, are visible in the archaeological record during each abrupt climate change event in West Asia. Chronological refinement, in both the paleoclimate and archaeological records, and transfer functions for both precipitation and agro-production are needed to understand precisely the evident causal linkages. 相似文献
4.
Global analyses of mean monthly zonal wind component and temperature at 200, 150 and 100 mb levels have been made for the
region between 60°N and 60°S, for the months May through September during two poor monsoon years (1972 and 1979) and a good
monsoon year (1975). Prominent and consistent contrasting features of the zonal wind and thermal fields have been identified,
with reference to the monsoon performance over India. It has been noticed that the areal spreading of easterlies over the
tropics and extratropics is significantly more during a good monsoon year. Shifting of the axis of the tropical easterly jet
stream to a higher level and generally stronger easterlies also characterize good monsoon activity. The upper troposphere
has been found to be considerably cooler during poor monsoon years. 相似文献
5.
M. R. Ramesh Kumar S. Sathyendranath N. K. Viswambharan L. V. Gangadhara Rao 《Journal of Earth System Science》1986,95(3):435-446
Using the satellite derived sea surface temperature (SST) data for 1979 (bad monsoon) and 1983 (good monsoon), the SST variability for two contrasting monsoon seasons is studied. The study indicates that large negative anomalies off the Somali and Arabian coasts are associated with good monsoon rainfall over India. The strong monsoonal cooling in these regions can be attributed to strong low level winds and intense upwelling. The reappearance of 27°C isotherm off Somali coast in May/June coincides with the onset of southwest monsoon over India. Further, the influence of zonal anomaly of SST off Somalia Coast (SCZASST) and Central Indian Ocean Zonal Anomaly of SST (CIOZASST) with monsoon rainfall over India is brought out. The former is negatively related to the monsoon rainfall over western and central parts of India, whilst CIOZASST is positively related. 相似文献
6.
7.
Comparisons of drought variability between central High Asia and monsoonal Asia: Inferred from tree rings 总被引：1，自引：0，他引：1
Keyan Fang Xiaohua Gou Fahu Chen Fen Zhang Yingjun Li Jianfeng Peng 《Frontiers of Earth Science》2010,4(3):277-288
Severe drought is a serious natural disaster that frequently strikes East Asia, highlighting the need to understanding its
drought regime and the associations with Asian monsoon. Tree-ring-based drought reconstructions provide invaluable paleoclimatic
archives for detecting regional and large-scale drought variability and their potential forcings. We herein reviewed many
drought reconstructions from central High Asia and monsoonal Asia and compared their similarities and differences, as well
as their linkages to Asia monsoon. We compared the decadal-scale variability of six drought reconstructions for the central
High Asia, where differing drought variations were found between the western and eastern portions. Seven drought reconstructions
were reviewed for monsoonal Asia, from which a difference in drought variability was observed between the northern and southern
parts. Therefore, we compared the drought variations of the four sub-regions of western and eastern parts of central High
Asia, as well as northern and southern portions of monsoonal Asia. ENSO activity and sea surface temperature of western Pacific
and northern Indian Oceans, coupled with Asian monsoon, play an important role in modulating drought variability of much area
of the East Asia. An improved denser multi-index tree-ring network of longer length for East Asia is necessary for the establishment
of more reliable large-scale drought reconstruction. 相似文献
8.
The characteristic features of the marine boundary layer (MBL) over the Bay of Bengal during the southwest monsoon and the
factors influencing it are investigated. The Bay of Bengal and Monsoon Experiment (BOBMEX) carried out during July–August
1999 is the first observational experiment under the Indian Climate Research Programme (ICRP). A very high-resolution data
in the vertical was obtained during this experiment, which was used to study the MBL characteristics off the east coast of
India in the north and south Bay of Bengal. Spells of active and suppressed convection over the Bay were observed, of which,
three representative convective episodes were considered for the study. For this purpose a one-dimensional multi-level PBL
model with a TKE-ε closure scheme was used. The soundings, viz., the vertical profiles of temperature, humidity, zonal and
meridional component of wind, obtained onboard ORV Sagar Kanya and from coastal stations along the east coast are used for
the study. The temporal evolution of turbulent kinetic energy, marine boundary layer height (MBLH), sensible and latent heat
fluxes and drag coefficient of momentum are simulated for different epochs of monsoon and monsoon depressions during BOBMEX-99.The
model also generates the vertical profiles of potential temperature, specific humidity, zonal and meridional wind. These simulated
values compared reasonably well with the observations available from BOBMEX. 相似文献
9.
Ensemble seasonal integrations are carried out with the COLA GCM, with a view to understand the dynamical connection between warm SST anomalies in the equatorial central-eastern Pacific Ocean and the upper level stationary wave anomalies seen during drought years over the Indian summer monsoon region. In addition, experiments with and without orography are performed in order to examine the role of the Himalayas in modulating the El Niño induced stationary wave anomalies over the summer monsoon region. The GCM simulations show a statistically significant weakening of the summer monsoon activity over India in response to the SST forcing in the equatorial Pacific Ocean. This weakening of the summer monsoon appears to be largely related to modifications of the local Hadley and Walker cells over the summer monsoon region. In addition, it is seen that the anomalous ENSO divergent forcing over the tropical Pacific Ocean can act as a potential source for Rossby wave dispersion. Here one finds the possibility of meridionally propagating Rossby waves, which emanate from the ENSO forcing region, to interact with the subtropical westerlies and generate anomalous highs and lows in the subtropics and extratropics. The quasi-stationary perturbations seen over west Asia, Pakistan and northwest India during drought years, seem to be generated by the above mechanism. An alternate mechanism that could be important for the persistence of the quasi-stationary perturbations seems to be based on the dynamic excitation of middle latitude normal modes which can extract energy from the zonally varying unstable basic flow. It is seen from the GCM simulations, that the Himalayan orography plays a crucial role in anchoring the El Niño induced extratropical westerly troughs far to the west in the high latitude belt. In the absence of orography it is seen that the ENSO induced extra-tropical cyclonic anomalies tend to intrude southward into the monsoon region thereby destroying the regional scale circulations completely. Another effect due to the Himalayas is to generate lee waves on the eastern side of the topographic barrier which encircle the globe in the subtropics and midlatitudes. 相似文献
10.
Meteorological fields variability over the Indian seas in pre and summer monsoon months during extreme monsoon seasons 总被引：1，自引：0，他引：1
U. C. Mohanty R. Bhatla P. V. S. Raju O. P. Madan A. Sarkar 《Journal of Earth System Science》2002,111(3):365-378
In this study, the possible linkage between summer monsoon rainfall over India and surface meteorological fields (basic fields
and heat budget components) over monsoon region (30‡E-120‡E, 30‡S30‡N) during the pre-monsoon month of May and summer monsoon
season (June to September) are examined. For this purpose, monthly surface meteorological fields anomaly are analyzed for
42 years (1958-1999) using reanalysis data of NCEP/NCAR (National Center for Environmental Prediction/National Center for
Atmospheric Research). The statistical significance of the anomaly (difference) between the surplus and deficient monsoon
years in the surface meteorological fields are also examined by Student’s t-test at 95% confidence level.
Significant negative anomalies of mean sea level pressure are observed over India, Arabian Sea and Arabian Peninsular in the
pre-monsoon month of May and monsoon season. Significant positive anomalies in the zonal and meridional wind (at 2 m) in the
month of May are observed in the west Arabian Sea off Somali coast and for monsoon season it is in the central Arabian Sea
that extends up to Somalia. Significant positive anomalies of the surface temperature and air temperature (at 2 m) in the
month of May are observed over north India and adjoining Pakistan and Afghanistan region. During monsoon season this region
is replaced by significant negative anomalies. In the month of May, significant positive anomalies of cloud amount are observed
over Somali coast, north Bay of Bengal and adjoining West Bengal and Bangladesh. During monsoon season, cloud amount shows
positive anomalies over NW India and north Arabian Sea.
There is overall reduction in the incoming shortwave radiation flux during surplus monsoon years. A higher magnitude of latent
heat flux is also found in surplus monsoon years for the month of May as well as the monsoon season. The significant positive
anomaly of latent heat flux in May, observed over southwest Arabian Sea, may be considered as an advance indicator of the
possible behavior of the subsequent monsoon season. The distribution of net heat flux is predominantly negative over eastern
Arabian Sea, Bay of Bengal and Indian Ocean. Anomaly between the two extreme monsoon years in post 1980 (i.e., 1988 and 1987)
shows that shortwave flux, latent heat flux and net heat flux indicate reversal in sign, particularly in south Indian Ocean.
Variations of the heat budget components over four smaller sectors of Indian seas, namely Arabian Sea, Bay of Bengal and west
Indian Ocean and east Indian Ocean show that a small sector of Arabian Sea is most dominant during May and other sectors showing
reversal in sign of latent heat flux during monsoon season. 相似文献
11.
Analysis of fifty four (1951–2004) years of daily energetics of zonal waves derived from NCEP/NCAR wind (u and υ) data and daily rainfall received over the Indian landmass (real time data) during southwest monsoon season (1 June–30 September)
indicate that energetics (momentum transport and kinetic energy) of lower tropospheric ultra-long waves (waves 1 and 2) of
low latitudes hold a key to intra-seasonal variability of monsoon rainfall over India.
Correlation coefficient between climatology of daily (122 days) energetics of ultra-long waves and climatology of daily rainfall
over Indian landmass is 0.9. The relation is not only significant but also has a predictive potential. The normalised plot
of both the series clearly indicates that the response period of rainfall to the energetics is of 5–10 days during the onset
phase and 4–7 days during the withdrawal phase of monsoon over India. During the established phase of monsoon, both the series
move hand-in-hand. Normalised plot of energetics of ultra-long waves and rainfall for individual year do not show marked deviation
with respect to climatology. These results are first of its kind and are useful for the short range forecast of rainfall over
India. 相似文献
12.
In this paper satellite-derived radiative energy budget such as shortwave radiative heating, longwave radiative heating and net radiation balance have been studied for the post-onset phase of summer monsoon 1979. Since clouds play an important role in determining diabatic heating field as well as being a reflection of status of the monsoon itself, the day to day evolution of clouds from TIROS-N satellite has been made. Satellite-derived radiative heating rates from surface to 100 hPa were computed for each 100 hPa thickness layer. These heating rates were then compared with the observed latitudinal distribution of total radiative heating rates over the domain of the study. From the results of our study it was found that the characteristic features such as net radiative heating rates of the order of 0.2°C/day at upper tropospheric layer (100–200 hPa) and cooling throughout the lower tropospheric layers with relatively less cooling between 500–700 hPa layer observed in a case of satellite-derived radiative energy budget agree well with the characteristic features of observational radiative energy budget over the domain of the study. Therefore, it is suggested that radiative energy budget derived from satellite observations can be used with great potential and confidence for the evolution of the complete life cycle of the monsoon over the Indian region for different years. 相似文献
13.
Climate induced changes in the circulation and dispersal patterns of the fluvial sources during late Quaternary in the middle Bengal Fan 总被引：2，自引：0，他引：2
From a transact along 15‡N latitude in the middle Bengal Fan, temporal and spatial variations in the granulometric parameters
and clay minerals in14C dated box cores from the eastern, the central and the western regions were studied to determine climate induced changes
in the hydrography. Clay assemblages have spatial and temporal changes and are markedly different in the eastern and the western
bay. From a high abundance of the clay smectite, which has its major source in the Deccan Basalt in peninsular India, it is
inferred that the western bay is predominantly a depocenter of ‘peninsular sources”. The eastern and the central regions of
the bay, however, mostly receive sediments of the ‘Himalayan source’. Related to unstable climate, the reported dominant illite-chlorite
(I + C) assemblage in the eastern region of the bay (I + C > 60% smectite <15%), between 18 and 12.6 ka BP, points to a predominant
supply from the Himalayan sources through equatorwards dispersal by the winter hydrography. Higher smectite, and reduced clays
of the Himalayan sources (smectite > 25%; I + C > 45%) are reported also after 12.5 ka BP from the eastern bay. These are
interpreted as evidences of an intensified SW monsoon and associated change in the dispersal pattern by stronger summer monsoon
hydrography which supports across bay dispersal by anticyclonic gyre. The influence of climate on hydrographic changes is
consistent during the short events of arid climate (weak NE monsoon) in Holocene in core 31/1 (western bay), in which the
enhanced contents of the clays of the Himalayan sources are observed (smectite < 40% I + C > 50%). These findings have implications
for climate regulated influence of fluvial processes over the areas, hitherto, considered unaffected by the Indian peninsular
fluvial sources 相似文献
14.
利用中国逐日站点降水资料、逐日季风监测指数及逐日副热带高压指数、74项环流指数及NCEP/NCAR再分析资料, 分析了2009年秋季至2010年春季的秋冬春西南特大干旱过程中各指数及大气环流异常特征.结果表明: 自2009年10月底东亚冬季风建立以来, 至2010年春季, 东亚冬季风强度持续偏强, 加之西太平洋副热带高压较常年偏西偏南, 西南地区长期受副高控制, 气温持续偏高, 加之冷空气虽然总体偏强, 但主要控制我国北方地区, 造成冷暖空气在西南地区少有交汇, 致使降水偏少, 干旱发生发展. 印缅槽强度较常年偏弱, 来自印度洋、孟加拉湾以及南海的水汽条件不足, 向西南地区输送的来自南海和孟加拉湾两条水汽通道的水汽通量均较常年偏弱很多, 加之西南地区、特别是云南地区自2009年秋季以来, 长期处于下沉运动的正距平区, 造成这段时间西南地区干旱少雨, 旱情持续. 2009年9月El Niño事件全面爆发, 南海-西太平洋地区形成异常反气旋流场, 该反气旋流场较常年偏西偏南, 造成副高位置偏西偏南, 从而使得云贵高原及其周边的印度季风区的降雨量明显偏少;高原地区及南海、菲律宾附近及热带辐合带地区OLR异常对西太平洋副热带高压的变化有一定影响, 进而影响西南地区降水, 其内在机制还有待深入研究. 相似文献
15.
Barendra Purkait 《Frontiers of Earth Science》2009,3(1):21-33
Coastal erosion at Sagar Island of Sunderban delta, India, has been critically studied. The area is in the subtropical humid
region. There are mainly three seasons viz: winter, summer and the monsoon. Different wave dynamic parameters were measured
from theodolite observations with leveling staff and measuring gauges during lunar days at two sections of the western and
eastern parts of the coastal zone during post-and pre-monsoons. A comparative study was made on the erosion/depositional pattern
between the two sections in relation to different hydrodynamic parameters prevailing in these two sections. Plane table mapping
was carried out to demarcate the different geomorphic units. The marine coastal landforms show dune ridges with intervening
flats bordered by gently sloping beach on one side and a flat beach on the other side. The western part of the beach is mainly
sandy; whereas the eastern part is silty and clayey with mud bank remnants. Actual field measurements indicate that the coastal
dune belt has retreated to the order by about 20 m since 1985. The eastern part of the beach has lowered by about 2 m since
1985 and the western part was raised almost to the same tune. It is observed that accretion in the western and central parts
of the beach took place; whereas severe erosion in the eastern part made the beach very narrow with remnants of mud banks
and tree roots. Frequent embankment failures, submergence and flooding, beach erosion and siltation at jetties and navigational
channels, cyclones and storm surges made this area increasingly vulnerable. 相似文献
16.
L S Hingane 《Journal of Earth System Science》1984,93(2):105-110
Global analyses of zonal wind field and thermal field structure at standard pressure levels of 200,150 and 100 mb have been carried out in India during July 1979—a poor monsoon year and July 1975—a good monsoon year. More than 250 stations in the belt 60°N and 60°S were selected. Contrasting features of the zonal wind field structure and thermal field are brought out, and it is shown that monsoon activity is reflected in the upper level and is controlled by planetary scale. 相似文献
17.
A two-dimensional, nonlinear, vertically integrated model was used to simulate depth-mean wind-driven circulation in the upper
Ekman layers of the Bay of Bengal and Andaman Sea. The model resolution was one third of a degree in the latitude and longitude
directions. Monthly mean wind stress components used to drive the model were obtained from the climatic monthly mean wind
data compiled by Hastenrath and Lamb. A steady-state solution was obtained after numerical integration of the model for 15
days. The sensitivity of the model to two types of open boundary conditions, namely, a radiation type and clamped type, was
tested. A comparison of simulated results for January with available ship drift data showed that the application of the latter
along the open boundary could reproduce all the observed features near the boundary and the interior of the model domain.
The model was integrated for 365 days to study the circulation during the southwest and northeast monsoon seasons. The model
was successful in simulating the broad features of circulation including gyres and eddies observed during both the seasons,
the development of north equatorial current during the northeast monsoon period and eastward moving monsoon drift current
up to 90°E during the southwest monsoon season. During the latter season, two anticyclonic gyres were observed in the central
and the southern parts of the Bay. A cyclonic type of circulation was prevalent in the central and western parts of the Bay
of Bengal during the northeast monsoon months of November and December. The simulated western boundary current along the east
coast of India, flows northward and southward during the southwest and northeast monsoon seasons respectively. It is presumed
that this western boundary current, simulated during both the seasons, is locally wind-driven. 相似文献
18.
Markus Reuter Andrea K. Kern Mathias Harzhauser Andreas Kroh Werner E. Piller 《Gondwana Research》2013,23(3):1172-1177
Precipitation over India is driven by the Indian monsoon. Although changes in this atmospheric circulation are caused by the differential seasonal diabatic heating of Asia and the Indo-Pacific Ocean, it is so far unknown how global warming influences the monsoon rainfalls regionally. Herein, we present a Miocene pollen flora as the first direct proxy for monsoon over southern India during the Middle Miocene Climate Optimum. To identify climatic key parameters, such as mean annual temperature, warmest month temperature, coldest month temperature, mean annual precipitation, mean precipitation during the driest month, mean precipitation during the wettest month and mean precipitation during the warmest month the Coexistence Approach is applied. Irrespective of a ~ 3–4 °C higher global temperature during the Middle Miocene Climate Optimum, the results indicate a modern-like monsoonal precipitation pattern contrasting marine proxies which point to a strong decline of Indian monsoon in the Himalaya at this time. Therefore, the strength of monsoon rainfall in tropical India appears neither to be related to global warming nor to be linked with the atmospheric conditions over the Tibetan Plateau. For the future it implies that increased global warming does not necessarily entail changes in the South Indian monsoon rainfall. 相似文献
19.
Nityanand Singh 《Journal of Earth System Science》1995,104(1):1-36
Large-scale interannual variability of the northern summer southwest monsoon over India is studied by examining its variation
in the dry area during the period 1871–1984. On the mean summer monsoon rainfall (June to September total) chart the 800 mm
isohyet divides the country into two nearly equal halves, named as dry area (monsoon rainfall less than 800 mm) and wet area
(monsoon rainfall greater than 800 mm). The dry area/wet area shows large variations from one year to another, and is considered
as an index for assessing the large-scale performance of the Indian summer monsoon. Statistical and fluctuation characteristics
of the summer monsoon dry area (SMDA) are reported.
To identify possible causes of variation in the Indian summer monsoon, the correlation between the summer monsoon dry area
and eleven regional/global circulation parameters is examined. The northern hemisphere surface air temperature, zonal/hemispheric/global
surface air and upper air temperatures, Southern Oscillation, Quasi-biennial oscillation of the equatorial lower stratosphere,
April 500-mb ridge along 75°E over India, the Indian surface air temperature and the Bombay sea level pressure showed significant
correlation.
A new predictor parameter that is preceding year mean monsoon rainfall of a few selected stations over India has been suggested
in the present study. The stations have been selected by applying the objective technique ‘selecting a subset of few gauges
whose mean monsoon rainfall of the preceding year has shown the highest correlation coefficient (CC) with the SMDA’. Bankura
(Gangetic West Bengal), Cuddalore (Tamil Nadu) and Anupgarh (West Rajasthan) entered the selection showing a CC of 0.724.
Using a dependent sample of 1951–1980 a predictive model (multiple CC = 0.745) has also been developed for the SMDA with preceding
year mean monsoon rainfall of the three selected stations and the sea level pressure tendency at Darwin from Jan–Feb to Mar–May
as independent parameters. 相似文献
20.
ENSO-7赤道西太平洋异常纬向风所驱动的热带太平洋次表层海温距平的循环 总被引：13，自引：0，他引：13
近几年的一系列分析研究表明，ENSO与异常东亚冬季风之间有相互影响，持续的强（弱）东亚冬季风通过引起赤道西太平洋地区的西（东）风异常对El Niño/La Niña的发生起着重要作用；赤道太平洋次表层海温异常（SOTA）的年际变化（循环）与ENSO发生有密切关系；ENSO的真正源在西太平洋暖池，暖池正（负）SOTA沿赤道温跃层东传到东太平洋，便导致El Niño/La Niña的爆发；在暖池正（负）SOTA沿赤道东传的同时，有负（正）SOTA沿10°N和10°S纬度带向西传播，从而构成SOTA的循环；热带太平洋SOTA循环的驱动者是赤道西太平洋的异常纬向风。进而可以认为：ENSO实质上是主要由异常东亚季风引起的赤道西太平洋异常纬向风所驱动的热带太平洋次表层海温距平的年际循环。 相似文献