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51.
西北太平洋上层热含量的时空变化 总被引:1,自引:0,他引:1
基于全球月平均海温资料、137°E断面海温观测资料、同化水位资料和太平洋850 hPa纬向风资料,利用EOF、功率谱和最大熵谱等分析方法,分析了西北太平洋上层热含量的时空变化,并讨论了热含量变化与水位和赤道太平洋纬向风异常的关系.结果表明,西北太平洋上层热含量具有明显的年际和年代际变化;热含量的年际变化与热带太平洋大尺度海气系统异常相联系,即在El Ni(n)o期间,热含量减少,而在La Ni(n)a期间热含量增多;热含量在20世纪70年代末发生了一次气候跃变,在跃变前热含量偏多,而在跃变后则偏少;热含量与水位间存在着非常一致的同位相年际变化,而这种变化与赤道西、中太平洋的纬向风异常有关. 相似文献
52.
Four comparative experiments and some supplementary experiments were conducted to examine the role of meridional wind stress anomalies and heat flux variability in ENSO simulations by using a high-resolution Ocean General Circulation Model (OGCM). The results indicate that changes in the direction and magnitude of meridional wind stress anomalies have little influence on ENSO simulations until meridional wind stress anomalies are unrealistically enlarged by a factor of 5.0. However, evidence of an impact on ENSO simulations due to heat flux variability was found. The simulated Nino-3 index without the effect of heat flux anomalies tended to be around 1.0° lower than the observed, as well as the control run, during the peak months of ENSO events. 相似文献
53.
This study reveals that the interannual variability of the western edge of the western North Pacific(WNP)subtropical high(WNPSH) in early summer experienced an interdecadal decrease around 1990. Correspondingly, the zonal movement of the WNPSH and the zonal extension of the high-pressure anomaly over the WNP(WNPHA) in abnormal years possess smaller ranges after 1990. The different influences of the tropical SSTAs are important for this interdecadal change, which exhibit slow El Nino decaying pat... 相似文献
54.
Bases on the NCEP/NCAR reanalysis products, Had ISST dataset, and data of tropical cyclone(TC)landfalling in the Chinese mainland during 1960-2019, the possible impacts of Indian Ocean Dipole(IOD) mode and Indian Ocean basin(IOB) mode on the last-TC-landfall date(LLD) and first-TC-landfall date(FLD), respectively, are investigated in this study. The LLD is in significantly negative correlation with autumn IOD on the interannual timescale and their association is independent of El Nino-Southern O... 相似文献
55.
Having recognized that it is the tropospheric temperature (TT) gradient rather than the land–ocean surface temperature gradient that drives the Indian monsoon, a new mechanism of El Niño/Southern Oscillation (ENSO) monsoon teleconnection has been unveiled in which the ENSO influences the Indian monsoon by modifying the TT gradient over the region. Here we show that equatorial Pacific coralline oxygen isotopes reflect TT gradient variability over the Indian monsoon region and are strongly correlated to monsoon precipitation as well as to the length of the rainy season. Using these relationships we have been able to reconstruct past Indian monsoon rainfall variability of the first half of the 20th century in agreement with the instrumental record. Additionally, an older coral oxygen isotope record has been used to reconstruct seasonally resolved summer monsoon rainfall variability of the latter half of the 17th century, indicating that the average annual rainfall during this period was similar to that during the 20th century. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
56.
Several physically based stochastic dynamic models (SDM) are described including year-to-year variations of water volume in terminal and non-terminal lakes, streamflow of lake-fed rivers, and salinity of an inland sea (the Sea of Azov). All of these models are based upon the SDM of water volume of terminal lakes developed by Kritzky and Menkel in 1946 in co-operation with Kolomogorov. Explicit formulae are derived for second order statistical moments of the output processes, including variance, correlation function, spectra, etc., under the assumption that the forcing functions from stationary random sequences. The least-squares prediction problem is solved for both stationary and non-stationary cases. Some of the processes are shown to possess high statistical predictability. Actual predictions are compared with independent observations. Problems for further study are stated. 相似文献
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肖天贵 《南京气象学院学报》1995,18(3):444-449
时间标度计算表明,西北太平洋热带气旋路径是一个无标度性的系统,其关联方差谱遵从频率的-2 ̄-3次方幂律,不同背景下的路径系统均如此。由此得到的不同季节、不同地域的热带气旋路径可预报时间尺度基本上为3 ̄4d,但异常热带气旋路径的可预报时间尺度则为1 ̄2d。 相似文献