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701.
采用一种基于降水异常追踪MJO(Madden–Julian Oscillation)东传的MJO识别方法(MJO Tracking)评估了参与MJOTF/GASS(MJO Task Force/Global Energy and Water Cycle Experiment Atmospheric System Study)全球模式比较计划的全海气耦合模式(CNRM-CM)、半海气耦合模式(CNRM-ACM)和大气模式(CNRM-AM)1991~2010年模拟MJO的能力,探究了海气耦合过程对模式模拟MJO能力的影响机理。CNRM-CM模式模拟的MJO结构更加接近观测,该模式不仅具有最高的MJO生成频率,也能够模拟较强的MJO强度以及较远的传播距离。海气耦合过程会造成CNRM-CM和CNRM-ACM模式中印度洋—太平洋暖池区域海温气候态的冷偏差。但是这种海温气候态的偏差基本没有改变模式模拟MJO的能力。CNRM-CM中MJO对流中心东(西)侧存在较强的季节内尺度海温暖(冷)异常,纬向梯度明显,而CNRM-ACM和CNRM-AM中不存在这样的海温东西不对称结构。结果表明在CNRM模式中海气耦合过程调控模式海温季节内尺度变率对模式MJO模拟能力的影响比调控模式海温气候态更加重要。 相似文献
702.
With respect to atmospheric impact, the 1982 eruption of the El Chichón volcano in Mexico is one of the most significant volcanic events of this century. The presence in the stratosphere, during several years, of an unusally high amount of sulfuric acid aerosols produced by this eruption is thought to be responsible for severe windshield damages on high-flying commercial jets. This problem took epidemic proportions in 1983–1984 and the cost to commercial aviation companies is estimated at several tens of millions of U.S. dollars. 相似文献
703.
A FURTHER STUDY ON INTERACTION BETWEEN ANOMALOUS WINTER MONSOON IN EAST ASIA AND EL NINO 总被引:3,自引:0,他引:3
李崇银 《Acta Meteorologica Sinica》1996,(3)
The interaction between anomalous winter monsoon in East Asia and El Nino is further stud-ied in this paper.The new results still more proved a previous conclusion:there are clear interac-tions between El Nino and winter monsoon in East Asia.The continual westerly burst andstronger cumulus convection over the equatorial central-western Pacific caused by stronger wintermonsoon in East Asia can respectively excite anomalous oceanic Kelvin wave and stronger atmo-spheric intraseasonal oscillation in the tropics,then excite the El Nino event through air-sea inter-action.In El Nino winter,there are warmer and weaker winter monsoons in East Asia.The El Ni-no will still reduce the intensity of intraseasonal oscillation and leads it to be barotropic structure. 相似文献
704.
705.
El Nino and La Nina are the events concerned internationally. The correspondingrelationship between El Nino events, temperature, precipitation and runoff in the Qilian mountain areaare analyzed according to the date from the weather and the hydrometric stations in the area, theresults show that effects of El Nino events to temperature, precipitation and runoff are different in thedifferent time and zones. When El Nino occurs, temperature rises, but precipitation and runoff decreasein the whole Qilian mountain area, especially in the east and middle parts of the area. Temperaturerises, precipitation and runoff still decrease in the eastern Qilian mountain area in the next year ElNino occurring, but decrease extent is fewer. There are not obvious relationship between temperature,precipitation and runoff with El Nino events in the western Qilian mountain area. 相似文献
706.
707.
El Nino as well as the Southern Oscillation is one of the strongest signals known so far over climatic noise ininterannual variations of the atmosphere and oceans.A great number of studies have shown definitely relationships be-tween the events and climatic anomalies in China.In this review,observational results obtained in the recent severalyears are first summarized.Then the possible physical mechanisms on the influence of El Nino are presented and,finally,the associated problems are discussed. 相似文献
708.
The relationship between summer rainfall anomalies in northeast China and two types of El Ni?o events is investigated by using observation data and an AGCM. It is shown that, for different types of El Ni?o events, there is different rainfall anomaly pattern in the following summer. In the following year of a typical El Ni?o event, there are remarkable positive rainfall anomalies in the central-western region of northeast China, whereas the pattern of more rainfall in the south end and less rainfall in the north end of northeast China easily appears in an El Ni?o Modoki event. The reason for the distinct differences is that, associated with the different sea surface temperature anomalies (SSTA) along the equatorial Pacific, the large-scale circulation anomalies along east coast of East Asia shift northward in the following summer of El Ni?o Modoki events. Influenced by the anomalous anticyclone in Philippine Sea, southwesterly anomalies over eastern China strengthens summer monsoon and bring more water vapor to Northeast China. Meanwhile, convergence and updraft is strengthened by the anomalous cyclone right in Northeast China in typical El Ni?o events. These moisture and atmospheric circulation conditions are favorable for enhanced precipitation. However, because of the northward shift, the anomalous anticyclone which is in Philippine Sea in typical El Ni?o cases shifts to the south of Japan in Modoki years, and the anomalous cyclone which is in the Northeast China in typical El Ni?o cases shifts to the north of Northeast China, leading to the “dipole pattern” of rainfall anomalies. According to the results of numerical experiments, we further conform that the tropical SSTA in different types of El Ni?o event can give rise to observed rainfall anomaly patterns in Northeast China. 相似文献
709.
The variation of warm pool in the equatorial western pacific and its impacts on climate 总被引:6,自引:2,他引:4
1.IntroductionSincetheEINinoeventwasregardedasaresultoftheair--seainteraction(Bjerknes,1969;RasmussonandWallace,1983;Philander,1990),thetropicalPacifichasbeenPaidmuchattentionbymeteorologistsintheclimaticstudies.Particularly,thereisthehighestoceantemperatureintheequatorialwesternPacific,theuwarmpool",andthestrongestconvectionandatmosphericheatingareovertheequatorialwesternPacific,sothattheequatorialwesternPacificisveryimportanttotheclimaticvariationintheglobe.Thenumericalsimulationwithasi… 相似文献
710.
Bulk formulae for wind stress, sensible and latent heat flux are presented that are suitable for strong mesoscale events such as westerly wind bursts that contribute to the El Niño-Southern Oscillation (ENSO). Their exchange coefficients for heat and momentum have a simple polynomial dependence on wind speed and a linear dependence on air–sea temperature difference. The accuracy of these formulae are validated with respect to air–sea fluxes estimated using the standard algorithm adopted by the Tropical Ocean-Global AtmosphereCoupled-Ocean Atmosphere Response Experiment (TOGA COARE). The comparison ismade for observations from 96 Tropical Atmosphere Ocean (TAO) array and National Oceanographic Data Center (NODC) moorings in the equatorial and North Pacific Ocean spanning years 1990–1999. The bulk formulae are shown to have very small median root–mean-square differences with respect to the TOGA COARE estimates: 0.003 N m-2, 1.0 W m-2, and 10.0 W m-2 for the wind stress, sensible heat flux, and latent heat flux, respectively.The variability of air–sea fluxes during the 1997–1998 ENSO is also examined, along with a possible relationship between air–sea fluxes and surface ocean mixed layer depth (MLD). The wind stress and latent heat flux during the 1997 El Niño are found to be greater in the warm pool of the western Pacific than in the central Pacific where the ENSO is most clearly seen. These differences disappear upon the start of La Niña. The MLD in the equatorial Pacific is found to be moderately correlated to air–sea fluxes just before the start of the 1998 La Niña and poorly correlated otherwise. 相似文献