The most sensitive initial error modes modulating intensities of CP- and EP- El Niño events

The two types of El Niño events simulated by the Geophysical Fluid Dynamics Laboratory Climate Model version 2p1 (GFDL CM2p1) model and its “spring predictability barrier” (SPB) associations are examined. By conducting the ensemble hindcast experiments related to the sea temperature on the whole Pacific, both of the predictions for CP- and EP-El Niño show a significant SPB phenomenon, but the CP-El Niño features a much weaker SPB compared to the EP-El Niño. Further analyses revealed that, for CP-El Niño events, the initial sea temperature errors of the North Pacific with triple-like shape, referred to as negative Victoria Mode (VM) induces the largest prediction errors in Niño4 areas and modulates the intensities of CP-El Niño events. While for EP-El Niño events, the initial sea temperature errors in the subsurface layer of the western equatorial Pacific and the upper layer of the Southeast Pacific (15–30ºS) with the meridional mode induce the largest prediction errors in Niño3 areas and modulates the intensities of EP-El Niño events. Obviously, results stress that, in order to reduce final prediction errors and obtain better predictions in terms of intensity on the two types of El Niño events, we should mainly focus on initial sea temperature accuracy in not only the subsurface layer of the west equatorial Pacific but also the surface layer of southeast Pacific and the region covered by the VM-like mode in the North Pacific.     

半干旱雨养农业区灌浆期模拟酸雨对春小麦叶片光合特性及产量的影响

为探明酸雨对春小麦光合特性及产量的影响,用pH为1.5、2.5、3.5、4.5和5.6的模拟酸雨在春小麦灌浆期对其进行喷淋,然后测定不同pH模拟酸雨处理后春小麦叶片的光合参数与春小麦产量。研究结果表明:①随着酸雨pH的下降,春小麦叶片净光合速率下降了9.61%~61.50%,气孔导度下降了7.03%~57.46%,蒸腾速率下降了3.70%~55.44%,胞间CO2浓度上升了27.91%~43.74%,叶绿素相对含量下降了12.12%~41.92%,产量下降了15.50%~37.05%。酸雨对春小麦叶片光合特性的影响随酸雨的氢离子浓度增大而愈显著。②酸雨pH与净光合速率、蒸腾速率、气孔导度、叶绿素相对含量及春小麦最终产量均呈极显著正相关,与胞间CO2浓度呈显著负相关。     

临洮县春末夏初干旱气候分析

文中统计了临洮县 196 1～ 2 0 0 0年共 4 0年逐旬降水量资料 ,用谐波分析法分析诊断临洮县逐旬降水量多年平均值的年周期与半年周期 ,划分出气候干湿期时段 ,分析造成春末夏初旱的环流特征 ,为做好短期气候预测 ,指导农业生产提供服务     

乌鲁木齐4号泉甲烷趋势性变化原因分析

近5年来，乌鲁木齐4号泉水中甲烷含量逐年呈趋势性降低。本从泉点地质构造、水地球化学环境入手，结合水气象资料，分析并论正了甲烷逐年趋势性变化的原因。     

长江口及济州岛邻近海域叶绿素—a分布及其与水团、跃层的相关性

提出该海域叶绿素—a含量的分布:调查区西部最高,>0.8mg/m~3,出现了两个高值区:中部是0.4～0.8mg/m~3;东部和最南部最低,<0.4mg/m~3。此分布同水团密切相关。调查区内叶绿素—a变化范围是0.2～18.7mg/m~3。在垂直分布上,叶绿素—a同跃层密切相关,呈现出三种分布类型。在不同的断面或同一断面上,由于环境条件的不同,叶绿素—a含量在断面上显示出不同的分布格局。叶绿素—a含量分布还与黑潮次表层水涌升有关。     

Geochemical Changes in Spring Water Associated with the 2000 Eruption of the Miyakejima Volcano, Japan

Water was sampled from eight springs and a lake in volcanic Miyakejima Island of Japan after the 2000 eruption. Major chemical and isotopic compositions of the water were analyzed. Significant increases of sulfate ion are observed in several springs where the thickness of ejecta exceeds 32 mm. A good relationship of Cl/S mole ratios between spring water and leachate of the ejecta is observed. Sulfur isotopic compositions of the spring water become close to that of leachate of the ejecta as time elapses after the eruption. Consequently the sources of the added sulfate ion in the spring water after the eruption are interpreted to be anhydrite and adhered sulfur of the ejecta.     

北方岩溶大泉流量动态模拟及其管理

在充分研究晋祠泉流量动态的基础上,分析了影响晋祠泉流量的主要因素,并利用时间序列分析方法,建立了晋祠泉流量动态的模拟模型,在此基础上,提出煤矿排水管理曲线图的方法来管理晋祠泉域岩溶水资源。     

春小麦日蒸散规律的研究

本研究利用称重式仪器——水力蒸发器，观测了不同天气状况、不同生育时期及浇水前、后一天内各时段春小麦的蒸散量。研究结果说明：春小麦夜间(20-08时）蒸散量较小或为负值；蒸散量从08时开始增加，到16时左右达最大值；16时或18时以后蒸散量开始减小，夜间02-06时达全天最低值。晴天春小麦的蒸散量高于阴天，以10至18时差距最大。春小麦灌水及降雨后蒸散量有所增加。且不同时段的蒸散量与气温及水力蒸发器地面温度呈二次曲线关系。     

张掖地区春小麦生长期的辐射平衡观测

张掖地区春小麦的反射率在整个生育期内比较稳定，变化范围在１５％－１９％；有效辐射在总辐射中所占比倒例随小麦的生长而迅速降低，从小麦的三叶期到抽穗期，该比例由３３％下降至２０％，抽穗以后，变化缓慢，最后降为１７％；与有效辐射的情况相反，净辐射在总辐射中的比例随小麦的生长而增加，比值从５０％增到６８％。     

A Numerical Simulation on the Mesoscale Dynamics of the Spring Bloom in the Sea of Japan

The northward migration of spring bloom was observed in the Sea of Japan from April to May 1997 by the Ocean Color and Temperature Scanner (OCTS) on board the Advanced Earth Observing Satellite (ADEOS). This phenomenon is well simulated with a numerical ecosystem model coupled with a hydrodynamic model. The hydrodynamic model is the Geophysical Fluid Dynamics Laboratory (GFDL) Modular Ocean Model (MOM). The ecosystem model consists of five components: dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), phytoplankton, zooplankton and detritus. Results of the numerical ecosystem model suggest that the mesoscale development of the spring bloom in the Sea of Japan is related to that of sea water temperature, and that the bloom is limited by the depletion of DIN. This revised version was published online in August 2006 with corrections to the Cover Date.