Characteristics and Numerical Simulation of the Tropical Intraseasonal Oscillations under Global Warming

Using the ECMWF reanalysis daily 200-hPa wind data during the two 20-yr periods from 1958 to 1977 and from 1980 to 1999,the characteristics and changes of Intraseasonal Oscillations (ISO) in the two periods associated with global warming are analyzed and compared in this study.It is found that during the last 20 years,the ISO has weakened in the central equatorial Pacific Ocean,but becomes more active in the central Indian Ocean and the Bay of Bengal;under the background of the global warming,increase in the amplitude of ISO intensity suggests that the ISO has become more active than before,with an obvious seasonal cycle,i.e.,strong during winter and spring,but weak during summer and autumn;the energy of the upper tropospheric zonal winds has more concentrated in wave numbers 1-3,and the frequency of ISO tended to increase. Comparison between the results of control experiment and CO_2 increase (1% per year) experiment of FGOALS-1.0g (developed at LASG) with the first and second 20-yr observations,is also performed. respectively.The comparative results show that the spatial structure of the ISO was well reproduced,but the strength of ISO was underestimated.On the basis of space-time spectral analysis,it is found that the simulated ISO contains too much high frequency waves,leading to the underestimation of ISO intensity due to the dispersion of ISO energy.However,FGOALS-1.0g captured the salient features of ISO under the global warming background by two contrast experiments,such as the vitality and frequency-increasing of ISO in the central Indian Ocean and the Bay of Bengal.     

大气季节内振荡的数值模拟比较研究

用国内外两个较好的大气环流模式、在观测海表温度的强迫下进行了长时间(1978—1989年)的数值积分,然后对数值模拟结果与NCAR/NCEP再分析资料进行比较分析,其结果清楚表明,模式模拟结果的均方根误差中有30%—40%是来自于模拟的大气季节内振荡的均方根误差。尤其是,大气季节内振荡模拟的均方根误差的分布形势与总的均方根误差的分布形势几乎完全一致。对热带地区大气季节内振荡动能的模拟结果与NCAR/NCEP再分析资料的比较分析表明,其差异也十分明显,说明模式对热带大气季节内振荡的模拟能力也还比较差。因此可以认为,大气季节内振荡在天气气候模拟中极为重要,而如何在数值模式中模拟好大气季节内振荡还需要进行很好地研究。     

A GCM Study on the Tropical Intraseasonal Oscillation

The ability of AGCM to simulate the tropical intraseasonal oscillation (ISO) has been studied using the output of global spectral model (ALGCM (R42L9)) of the Institute of Atmospheric Physics, Chinese Academy of Sciences, and the outoput is compared with the results from NCEP/NCAR reanalysis for the year 1978-1989. The model displays an evident periodic signal of the tropical ISO. Basic propagating characters of the tropical ISO are captured, and changes in phase speed between Eastern and Western Hemispheres are also well presented, and the simulation of eastward propagation is better than that of westward propagation. This model has increased the ability to simulate the strength of the tropical ISO, especially at 200 hPa, and basically simulates the horizontal structure of wind characterized by the convergence in low-level and divergence in upper-level. The vertical structure of the zonal wind is also well reproduced. Moreover, observed results show that the representing of seasonal preference to form strong ISO in winter and spring is related to ISO's interannual variability, but it is shown in this model with strong ISO in winter and summer and weak ISO in spring and autumn. Structures of some physical elements such as vertical velocity, divergence, specific humidity, etc., and the special distribution of ISO have also differences with these from NCEP reanalysis data, which make it clear to develop this model to simulate the structure and spatial distribution of the ISO.     

Impacts of 30-60-Day Oscillations over the Subtropical Pacific on the East Asian Summer Rainfall

The relationships between the precipitation over East Asia (20°-45°N,110°-135°E) and the 30-60-day intraseasonal oscillation (ISO) over the Pacific during the boreal summer are studied in the paper.The daily wind and height fields of NCEP/NCAR reanalysis data,the 24-h precipitation data of 687 stations in China during 1958-2000,and the pentad precipitation of CMAP/NOAA from 1979 to 2002 are all analyzed by the space-time filter method.The analysis results,from every drought and flood summer in four different regions of East Asia respectively during 1958-2000,have shown that the flood (drought) in the East Asian summer monsoon region is absolutely companied with the strongly (weakly) westward propagations of ISO from the central-east Pacific,and depends little on the intensity changes of the East Asian summer monsoon. And the westward ISO is usually the low-frequency cyclones and anticyclones from the Bay of Alaska in northeastern Pacific and the Okhotsk in the northwestern Pacific of mid-high latitudes,and the ISO evolving in subtropical easterlies.In mid-high latitudes the phenomena are related to the westward propagating mid- ocean trough and the retreat of blocking high.Therefore the westward propagating ISO from the central-east Pacific to East Asia is indispensable for more rainfall occurring in East Asia in summer,which results from the long-wave adjustment process in the mid-high latitudes and ISO evolving in tropical easterlies.     

Intra-Seasonal Oscillation (ISO) of south Kerala rainfall during the summer monsoons of 1901–1995

Time series of daily averaged rainfall of about 40 rain gauge stations of south Kerala, situated at the southern-most part of peninsular India between latitudes about 8‡N and 10‡N were subjected to Wavelet Analysis to study the Intra Seasonal Oscillation (ISO) in the rainfall and its inter-annual variability. Of the 128 days, 29th May to 3rd October of each of the 95 years 1901-1995 were analysed. We find that the period of ISO does not vary during a monsoon season in most of the years, but it has large inter-annual variability in the range 23 to 64 days. Period-wise, the years cluster into two groups of ISO, the SHORT consisting of periods 23, 27 and 32 days and the LONG with a single period of 64 days, both the sets at a significance level of 99%. During the 95 years at this level of significance there are 44 years with SHORT and 20 years with LONG periods. 11 years have no ISO even at the 90% level of significance. We composited NCEP SST anomalies of the summer monsoon season June to September for two groups of years during the period 1965–1993. The first group is of 5 years with a LONG ISO period of 64 days for south Kerala rainfall at significance level of 99% and the second group is of 12 years with SHORT ISO periods of 23, 27 and 32 days at the same level of significance. The SST anomaly for the LONG (SHORT) ISO resembles that for an El Nino (La Nina).     

地质调查行业管理与国际标准接轨的探讨——运用ISO9001:2000标准建立质量管理体系

新疆地质调查院作为中国地质调查局确定的建立质量管理体系的首批试点单位，2000－2001年探索性地将ISO9001：2000版国际标准应用于地质调查行业中，在行业与ISO9000旋国际标准的联系，1994版与2000版标准版本的对比，转换以及与地质调查行业的结合，质量管理体系建立和实施要点总结等方面均取得了进展。     

浅谈质量方针和质量目标在测绘行业中的制定

从质量管理、质量控制基本原理出发 ,根据ISO90 0 0系列标准的要求 ,结合测绘单位的实际 ,提出了制定质量方针和质量目标的基本原则和方法。     

浅谈质量管理体系在测绘生产单位中的应用

本文在简要叙述了GB/T19001-2000(idt ISO 9001:2000)质量管理体系的基础上,以测绘产品的质量控制为例论述了质量管理体系在测绘生产单位的具体应用。通过实施质量管理体系,实现对生产过程的质量控制,实现持续改进,不断地提高产品质量。     

GGR Biennial Review: Reference Materials in Geoanalytical and Environmental Research – Review for 2008 and 2009

This review gives an overview of the literature on reference materials of geochemical and environmental interest for the two-year period 2008–2009. Reference materials play an increasingly important role in all fields of geoanalytical research. This is demonstrated by the large number of publications containing data on reference materials. Although many reference materials exist, there is still a great need for certified samples, so-called delta zero materials for stable isotopic work and homogeneous microanalytical reference materials. This review focuses on six topics: developments of certification processes of reference materials mainly postulated in ISO guidelines and the IAG protocol, new developments of the GeoReM database, investigations of powdered rock reference materials, Chinese reference materials published in Chinese journals, microanalytical reference materials and isotopic reference materials.     

越赤道气流ISO特征在台风季节预报中的可行性研究

越赤道气流作为南北半球物质、能量和水汽的输送通道,它的季节内变化引起台风水汽源变化,影响台风的生成频数和路径。该文研究了越赤道气流ISO特征在台风季节预报中的可行性。台风路径在传统的分类基础上细分为7种,对不同路径的台风所对应的低频流场进行超前和滞后合成,发现不同台风路径对应着不同的低频越赤道气流通道,低层20°N附近的低频气旋外围气流总是预示着台风路径未来的走向。低层低频流场的演变表明,越赤道气流的振荡周期为准40 d,它的ISO特征影响低纬地区的低频气旋的位置和强度,进而影响台风路径。高层低频流场刚好与低层反向,越赤道气流不再是以通道出现而是呈现区域特征。越赤道气流ISO特征可以作为台风季节预报的参考量之一。