上海地区盛夏高温分布和热岛效应的初步研究

根据1997～1998年的7～8月高温加密观测资料和卫星遥感资料,应用自然正交函数分解技术(EOF),对上海地区盛夏高温分布的气候平均场和第一特征场进行了分析.上海地区盛夏平均高温场分布具有显著的城市热岛效应特征.作者详细讨论了市区建成面积、土地利用类别、人口密度和人为热等都市化因素对热岛效应范围和强度的影响,并做出定量的估计,提出了缓解城市热岛效应的若干对策.第一特征场分析表明,风向是影响上海地区热岛效应范围和强度变化的最主要的气象因子.     

中美大气化学联合考察实验结果的初步分析与比较

根据临安区域本底站观测资料分析结果得出,中国中纬度地区秋、冬季O₃及其前体物NO_x等浓度偏高,可以对农作物和地表生态系统产生影响.观测结果表明:近地层大气O₃浓度主要决定于地面总辐射量控制下的光化学反应过程;O₃的生成受到前体物NO_x的控制,但O₃与NO_x存在着明显的非线性关系.从PEM-WESTA和B的实验及1995年的观测资料表明,O₃的生成效率随着NO_x浓度的增大而减小.尽管O₃的生成速率秋季比冬季的大,但由于秋季较高的NO_x抑制了过氧基的生成,因此冬季O₃的累积量几乎可以和秋季相比拟.在临安观测的NMHC和NO_x的比值比国外同纬度地区测值要大.这说明在临安本底站O₃的光化学生成中,NMHC不是控制物种.从而提示我们,在这些季节临安O₃光化学产物能够被NO_x浓度所控制.中美大气化学联合考察(PEM-WEST-B)实验期间,台湾省的卡盯站SO₂的平均浓度为0.29ppb,O₃的平均浓度为42.2ppb,可以认为此值为低纬度海岛的本底值.1994年PEM-WEST-B实验期间临安站的观测资料和台湾省的卡盯站资料相比,临安站SO₂的浓度约为卡盯站SO₂浓度的50倍左右,从而可以看出人类活动对大气本底的显着影响.     

龙凤山大气近地层O3浓度变化及与其它因素的关系

研究首次在龙凤山区域大气本底站测得的地面Ｏ３浓度及其变化的资料表明,中国东北农村地面大气Ｏ３浓度总体水平不很高,但在少数特殊的天气条件下,时均浓度可超过国家二级标准。Ｏ３浓度存在明显的季节和日变化,其月平均浓度１９９５年１月最低（２７．５ｐｐｂ）,１９９４年１１月最高（４３．２ｐｐｂ）。Ｏ３日变化幅度夏季的晴天最大（２８ｐｐｂ）,冬季的阴天最小（８ｐｐｂ）。气象要素（尤其是风速、气温和相对湿度等）和ＮＯｘ与地面Ｏ３浓度有较密切的关系。用多变量分析法探讨了地面Ｏ３各指标随气象因子和ＮＯｘ共同变化的规律,并拟合了寒冷和温暖期里与地面Ｏ３日最高浓度、日最低浓度及日变化幅度有关的方程。     

Theoretical relationship between SSA and MESA with both application

Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｇｕｌａｒｓｐｅｃｔｒａｌａｎａｌｙｓｉｓ（ＳＳＡ）,ａｓａｎｅｗｄｉａｇｎｏｓｔｉｃｍｅｔｈｏｄ,ｈａｓｂｅｎｅｘｔｅｎｓｉｖｅｌｙａｐｐｌｉｅｄｉｎｃｌｉｍａｔｉｃｄｉａｇｎｏｓｅｓａｎｄｐｒｅｄｉｃｔｉｏｎｗｉ...     

爆发性气旋的统计研究

用１９８０～１９８９年资料,统计了发生在北半球的爆发性气旋的若干特征,并通过不同区域,不同时间及强度的爆发性气旋发生的频率的对比,得到了一些有意义的结果。     

近35年江苏沿海气温变化对北半球增暖的响应

采用主分量分析与回归估计相结合的方法,研究近３５年来江苏沿海气温变化对半球增暖的响应状况。根据北半球平均增暖的条件,推求未来气候情景下该区各地增暖的可能幅度及其可靠性。结果表明（１）北半球增暖背景下,本区夏季气温变化趋势和年际振动的响应,具有很大的不确定性;     

γ射线康普顿背散射扫描仪测量的信噪比研究

本文详细给出了ＣＢＳ测量中噪声的物理来源和降低噪声的有效措施,还对信噪比进行了定量的分析和讨论。     

A preliminary research establishing the present-time intraplate blocks movement model on the Chinese mainland based on GPS data

The Chinese mainland is regarded as the best area for studying the continental crustal movement and dynamics. In the past, based on the ground surface observation, it was very difficult to study the movement of the intraplate blocks within a range of larger space and a time scale of several years quantitatively. In this paper, a method of calculating the Euler vectors of present-time motion among blocks by using Cardan angles has been given completely based on two periods of GPS repetition measurement data of the National Ascending Plan of China (NAPC) — the study and application of current crustal movement and geodynamics in 1994 and 1996. A present-time blocks movement model on the Chinese mainland (PBMC-1), which describes the motion of seven blocks—Tibet, Chuan-Dian, Gan-Qing, Xinjiang, South China, North China and Heilongjiang block, is established preliminarily. The velocity field of the relative motion among the intraplate blocks and boundary motion in the Chinese mainland are firstly given within several years time scale. It is shown by the results calculated with the model that the velocity-rate of each block is reduced gradually from the south to north and from the west to east, and the motion direction changes gradually from NNE to E, even SEE or SE. The collision of Indian plate plays a leading role in the movement of the intraplate blocks in the Chinese mainland, while the motion manner and velocity-rate of block boundary zone (fracture zone) depend on the motion of every block again. The present-time motion of a time scale of several years computed with the model is not only largely consistent with the average motion of a time scale of several million years derived from geology, but also very coincident with the results of geophysical and astronomic observation. It is shown preliminarily that the observed results of space geodesy techniques such as GPS etc. are capable of discovering the crustal movement at present. This study is supported by the National Natural Science Foundation of China (NNSFC), National Ascending Plan of China (NAPC) and Chinese Joint Seismological Science Foundation (CJSSF).     

青藏高原东北隅似三联点构造特征

在大陆内部,对于一定尺度的构造块体,似三联点构造是一种普通的构造形式。由于大陆内部块体旋转的普遍性,似三联点构造可形成顺旋型和逆旋型两种构造型式。     

New paleomagnetic results from Ceno-Mesozoic volcanic rocks along southern rim of the Tarim Basin,China*

Paleomagnetic samples were collected from four localities located in the southern rim of the Tarim basin. The samples were taken from volcanic rocks erupted between Jurassic and Quaternary. Detailed analysis of all samples has been carried out with progressive thermal demagnetization. A characteristic remanence (ChRM) with higher unblocking temperature has been isolated from all samples. The pole position from the middle Jurassic is at 52.5°N, 187.9°E(dp = 3.7°,dm =6.5°); the directions of the ChRM of Cretaceous correspond to a paleopole at 69.7°N, 211.6°E (dp = 9.8°,dm = 15.9°); the Quaternary pole from the Pulu site is at 79. 9°N, 183.1°E(dp = 1.6°.dm =2.4°). On the basis of these new paleomagnetic data, tectonic evolution of Tarim block is presented.