土壤湿度对中国西北地区夏季气候年际变率模拟效果的影响

利用耦合陆面过程模式CLM3的全球大气环流模式NCAR CAM3进行2组1979～2000年5～8月的集合试验,研究了表层土壤湿度对中国西北地区夏季气候年际变率模拟的影响。结果表明:在相同海温强迫条件下,采用年际变化的表层土壤湿度(ISSM)时,CAM3模式对于夏季西北地区气温和降水年际变率的模拟能力明显好于采用气候态的表层土壤湿度(CSSM)。计算表明,1979～2000年CSSM试验和ISSM试验模拟的西北地区夏季气温距平与ERA40资料的相关系数分别为0.60和0.65; CSSM试验模拟的西北地区夏季降水距平与CMAP资料的相关系数仅为0.29,而ISSM试验模拟结果与CMAP资料的相关系数为0.48。在相同海温强迫条件下,ISSM试验比CSSM试验能更好地模拟出中国西北地区夏季降水年际变率。     

冷眼东北亚 临津阁幽思

再访韩国,终于去了临津江上的临津阁。临津江发源于朝鲜境内,属于汉江的支流,向西南穿过朝韩军事分界线“三八线”流入韩国。令临津江声名大噪的,是朝鲜战争中的临津江一役。彭德怀指挥的这场战役,成为中国人民志愿军把战线从鸭绿江推进到“三八线”的关键之战。而近几年来,临津江泄洪问题曾一度成为朝韩关系的焦点。2009年9月,朝鲜在事先未通知的情况下将临津江上游的黄江水库开闸放水。导致韩国境内的临津江下游水位突然上涨,造成六名韩国人遇难。最近的一则新闻则是韩国军方9月中旬在朝韩接壤的临津江地区击毙了一名企图越境前往朝鲜的韩国男子。     

澳大利亚的政治“复仇”

澳大利亚政坛近期持续动荡,但在经历了一个躁动不安的不眠之夜之后,已逐渐恢复平静。6月26日晚,陆克文在在工党内部对决中战胜现任总理吉拉德,以57票对45票,重新夺得澳大利亚执政党党首地位。这一结果离2010年6月24日陆克文被他当时的副手吉拉德发动党内投票赶下台间隔3年零2天,     

Decadal variability of the IOD-ENSO relationship

Using three kinds of over 100-year sea surface temperature （SST） datasets as well as three-dimensional wind data from NCEP/NCAR, this paper documents the decadal variability of the Indian Ocean Dipole （IOD）-EI Nino/Southern Oscillation （ENSO） relationship. During 1948--1969, positive （negative） IOD and warm （cold） ENSO events were more independent of each other. But after 1970, they tended to occur in the same year. ENSO would influence the whole life span of IOD, and IOD also affects the developing phase of ENSO. Considering the climatological background SST, low-level winds and also equatorial vertical circulations, it is revealed that the decadal variability of the IOD-ENSO relationship may be caused by the enhanced Walker circulation with increased rising motion over the Maritime Continent after 1970. Warmer SST around the Maritime Continent gives rise to anomalous low-level convergence and intensified convection there, which apparently increases the SST linkage between the eastern Indian Ocean and the western Pacific and thereby the interaction between the IOD and ENSO event.     

Inter-hemispheric comparison of climate change in the last millennium based on the ECHO-G simulation

The commonality and difference in the variations of temperature and precipitation between the Northern Hemisphere （NH） and Southern Hemispheres （SH） in the last millennium are investigated by analysis of the millennium simulation with the ECHO-G coupled climate model. The NH mean temperature variations are generally consistent with those of the SH counterpart on the interannual, decadal and centennial time scales. But, the transition times between the medieval warm period （MWP）, the little ice age （LIA）, and the present-day warm period （PWP） in the NH leads that in the SH; and the anomaly amplitude in the NH is significantly larger than the SH counterpart. For the precipitation variations, the NH mean precipitation varies in-phase with the SH mean precipitation on decadal and centennial scales （mainly in the mid-high latitudes） but out-of-phase on the interannual scale （mainly in the low latitudes）. During the MWP the warming has comparable amplitude in the NH and SH; however, during the PWP the NH warming is considerably stronger than the SH warming. Further, the present-day temperature rises in the NH high latitudes but decreases in the SH high latitudes, which is very different from the warming pattern during the MWP. Since during the MWP the greenhouse gases （GHG） concentration stayed at a low level, we infer that the present-day opposite temperature tendency in the high latitudes between the two hemispheres may be related to the increase of the GHG concentration.     

经济增长的巨大环境代价

为办好2008年奥运会,北京花了大力气用于改善环境,奥运年的这个春天,感觉北京的环境有了明显改观。但不久前看到一则消息称,一些参加北京奥运会的外国选手因担心中国的食品安全而要自带食品;更有甚者,由于担心中国的环境污染,打算在奥运期间于韩国居住。凭直觉,这有很大的炒作成分,当然不排除有人顺手抹黑中国一把,那是习惯成自然了。     

秸秆代木初加工的设备配置

近年来。随着国民经济的飞速发展．对木材的需求量迅速增大。我国是世界上木材资源短缺的国家．人均森林面积0．132公颂,不到世界平均水平的1／4．木材供应大量依赖进口．是仅次于石油和钢铁的第三大用汇行业。目前我国木材年需求量超过1亿立方米．实际供应量仅6000万立方米．缺口超过4000万立方米．木材供不应求的局面将会长期存在。同时。我国又是农业大国,     

基于支持向量机的需水预测研究

以山西省11年实际用水量为例,17个影响需水预测的因子作为支持向量机模型的输入,需水量作为模型的输出,建立了基于支持向量机理论的非线性需水预测模型;根据预测精度,确定了损失系数ε,惩罚因子C及径向基核函数的宽度σ.采用11年用水量资料,前8年用水量作为训练样本,后3年用水量作为检验样本,3个检验样本的需水总量的相对误差分别为0.91%、1.86%和0.93%.结果表明,在训练样本较少的情况下,支持向量机需水预测模型具有较高的预测精度和较强的泛化能力.     

这一次，汶川离我们很近!

2008年5月12日14时28分。四川汶川惊天一震,给中国带来了巨大的灾难。     

另一种火炬接力

2008年北京奥运会的圣火接力在境外传递的过程中遇到麻烦——在一些国家的传递过程中出现了由“藏独”分子、“记者无疆界”等组织的抗议,甚而是暴力袭击。在法国巴黎的传递最为混乱;出现了暴徒堵塞交通、袭击残疾运动员、抢夺火炬、市政厅挂出反奥运旗帜等杂音,导致火炬传递被迫缩短行程的情况。