Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

1 Introduction Antarctic Oscillation is a major mode of Southern Hemispheric (SH) extratropical atmospheric circula- tion. The SH Annual Mode represents a zonally sym- metric exchange of mass between polarward of 60°S and 40°S[1], therefore AAO indicates both the intensity of circumpolar low and zonal mean west wind at mid-high latitudes in SH. Positive phase of AAO tends to deepen circumpolar low and enhance west wind at mid-high latitudes in SH. Many studies show that AAO has bar…     

A Possible Impact of Cooling over the Tibetan Plateau on the Mid-Holocene East Asian Monsoon Climate

By using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, the authors investigated the response of the East Asian monsoon climate to changes both in orbital forcing and the snow and glaciers over the Tibetan Plateau at the mid-Holocene, about 6000 calendar years before the present (6 kyr BP). With the Earth’s orbital parameters appropriate for the mid-Holocene, the IAP9L-AGCM computed warmer and wetter conditions in boreal summer than for the present day. Under the precondition of continental snow and glacier cover existing over part of the Tibetan Plateau at the mid-Holocene, the authors examined the regional climate response to the Tibetan Plateau cooling. The simulations indicated that climate changes in South Asia and parts of central Asia as well as in East Asia are sensitive to the Tibetan Plateau cooling at the mid-Holocene, showing a significant decrease in precipitation in northern India, northern China and southern Mongolia and an increase in Southeast Asia during boreal summer. The latter seems to correspond to the weakening, southeastward shift of the Asian summer monsoon system resulting from reduced heat contrast between the Eurasian continent and the Pacific and Indian Oceans when a cooling over the Tibetan Plateau was imposed. The simulation results suggest that the snow and glacier environment over the Tibetan Plateau is an important factor for mid-Holocene climate change in the areas highly influenced by the Asian monsoon.     

The Effect of Heating Anomaly on the Asian Circulation-A GCM Experiment

ＴｈｅＥｆｅｃｔｏｆＨｅａｔｉｎｇＡｎｏｍａｌｙｏｎｔｈｅＡｓｉａｎＣｉｒｃｕｌａｔｉｏｎ－ＡＧＣＭＥｘｐｅｒｉｍｅｎｔ①ＷａｎｇＨｕｉｊｕｎ（王会军）ＬＡＳＧ，ＩｎｓｔｉｔｕｔｅｏｆＡｔｍｏｓｐｈｅｒｉｃＰｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙ...     

气温和降水时变影响参数的多步预测模型

本文提出了一种气温和降水时变影响参数的多步预测建模新方案。该方案用时间序列均生函数外延矩阵生成的主分量作基函数对序变量建模，同时考虑变量前期数据对后期数据的影响，在模型中引入一个时变影响参数Ｋ１。并用方差分析法求出Ｋ１的显著周期和未来时刻的Ｋ１＋１值，从而建立气温和降水序列的时变影响参数的多步预测模型。该模型用于四川省２０个地、市的气温和降水预报数值试验，其历史拟合率和试报结果与实况值的比较表明，     

PROPAGATION OF INTERNAL INERTIO-GRAVITY WAVE SPECTRA IN VERTICAL WIND SHEAR ENVIRONMENTS*

The variation of the spectral structure of the internal inertio-gravity waves (ⅡGWs) propagating in the atmospheric wind shear environments is discussed in this paper.From the hydrodynamic equation set in Boussinesq approximation,a spectral propagation equation ⅡGWs satisfy is derived,then the spectral correspondence in the upper atmosphere is numerically calculated,after a forced spectrum is given as a Van-Zandt one at the lower boundary.The results show that if ⅡGWs do not encounter the critical-layer absorption,then their spectral structure may be not changed significantly; otherwise it may be changed greatly,and a few of spectral components are filtered.Also the isotropy of the assumed VanZandt spectrum is distorted in upward-propagating process.That is the directional filtering effect of the atmospheric wind on the gravity wave spectrum.     

EFFECTS OF WIND SHEAR ON ATMOSPHERIC GRAVITY WAVE SPECTRUM

The effects of constant wind shear on atmospheric gravity wave spectrum are examined.At first a three-dimensional equilibrium spectral model of gravity waves is established in which wind shear rate β is implicit.Based on this model,the expressions for one-dimensional frequency spectrum of atmospheric gravity waves arederived in which β is explicit.Numerical results show that (1) if we assume that mean wind U(z)=βz(z represents the altitude) and the internal gravity wave spectrum at the altitude of U=0 (that is,z=0) isVanZandt one,then the effect of Doppler shifting due to mean wind may be ignored;(2) when Richardson numberJ(J=N~2/β~2,N is Brunt-V(?)is(?)l(?) frequency,and is equal to 10~(-2)s~(-1) in this paper) satisfies J≥10.0,theeffects ofwind shear arealso ignored;(3)for f~2(?)ω~2(?)N~2 (f is the inertia frequency,and f=10~(-4)s~(-1)in this paper,and co is the observed frequency),the wind shear only affects the spectral amplitude,and does notalter the spectral shape;and (4) as wind shear becomes strong,a part of wave potential energy turns into wavekinetic one,and a part of the vertical kinetic energy further turns into the horizontal one.     

Geochemical Reference Samples, Drainage Sediment GSD 1 - 8 from China

A set of eight geochemical standard reference samples of stream sediments was prepared. The original purpose was to use these samples as primary standards for the data quality monitoring of a nation-wide regional geochemical survey program in China. But their use has been soon extended to other fields. Forty-one laboratories in China have joined in a collaborative venture to analyse these samples, using a variety of analytical procedures. Recommended values for over 50 trace and minor elements were derived by a method of repetitive elimination of outliers and calculation of central "tendency" from several central values.     

应用间溴偶氮羧—m光度法测定碳酸盐岩石及粮食中的铝

本文提出了用碳酸钠和氢氧化钠熔矿，在熔矿，提取过程中分离钙、镁、铁、锰等绝大部分干扰元素，应用间溴偶氮羧－ｍ作显色剂测定碳酸盐岩石及粮食中的铝的分光光度法，结果准确，重现性好。     

末次盛冰期气候模拟及青藏高原冰盖的可能影响

在国际古气候模拟比较设计设定的边界条件下（其中包括：海洋表面温度，陆地冰盖，CO2浓度，地球轨道参数等变化）。本文汇报了利用中国科学院大气物理研究所的9层全球大气环流格点模式对末次盛冰期气候进行数值模拟的研究成果。结果表明：末次盛冰期全球年平均温度在低5．3℃，降雨量下降9％，其中大陆年平均降水量仅为目前的71％。通过与其他模式模拟结果和重建古气候资料的对比表明，该模式捕捉到了末次盛冰期干，冷的冰期气候特征。在此基础上，我们根据刘东生等的科研成果，初步探讨了青藏高原在末次盛冰期倘若存在一定范围的冰盖，那么该冰盖会对东亚区域古气候模拟结果产生怎样的冲击。