Bacterial community in deep subseafloor sediments from the western Pacific “warm pool”

The bacterial community in deep subseafloor sediments at a depth of 230 cm from the western Pacific “warm pool” is studied by construction of 16S rDNA clone library and PCR-RFLP (Restriction Fragment Length Polymorphism) analysis. The results indicate that the bacterial community in these sediments is mainly composed of five groups: α-Proteobacteria, β-Proteobacteria, CFB group (Cytophaga / Flexibacteria / Bacteroides), Acidobacteria and gram positive bacteria, with a few genera detected in each group. The most abundant bacteria group is α-Proteobacteria, and the next is β-Proteobacteria. The dominant species in α-and β-Proteobacteria are Sphingomonas paucimobilis and Pseudomonas alcaligenes respectively. The CFB group is simply composed of members belonging to Flavobacterium. The gram positive bacteria are rich, and mainly consists of the genus Geobacillus. The analysis of bacterial community indicates that organic matter is still abundant in the subseafloor sediments at the depth of 230 cm in the western Pacific “warm pool”. These bacteria in this deep biosphere may play an important role in the nitrogen cycle of deep sea sediments at “warm pool”. Supported by the National Key Basic Research Support Foundation of China (Grant No. G2000078500) and China Ocean Mineral Resources R&D Association Project (Grant No. DY105-4-2-4)     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods’ abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella’s photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods. Supported by NSFC Innovation Research Group Program (Grant No. 40621002), MOE Innovative Research Team Program (Grant No. IRT0546), the National Natural Science Foundation of China (Grant Nos. 40472020, 40730209, 40802005 and 40872001) and SINOPEC Project (Grant No. G0800-06-ZS-319)     

Summer precipitation changes over the Yangtze River Valley and North China: Simulations from CMIP3 models

We present a study of summer precipitation changes over the Yangtze River Valley (YRV) and North China (NC) simulated from 20 models of the CMIP3 (phase 3 of the Coupled Model Intercomparison Project). It is found that the LASG-FGOALS-g1.0 (fgoals) model has the highest ability in simulating both the interannual variability of individual regions and the seesaw pattern of the two regions observed during the past few decades. Analyses of atmospheric circulations indicate that the variability in precipitation is closely associated with the 850 hPa meridional winds over the two regions. Wetness in the YRV and dryness in NC are corresponding to strong meridional wind gradient and weak meridional wind over these two regions, respectively. The ability of a coupled general circulation model (CGCM) to simulate precipitation changes in the YRV and NC depends on how well the model reproduces both observed associations of precipitation with overlying meridional winds and observed meridional wind features in summer. Analysis of future precipitation changes over the two regions projected by the fgoals model under the IPCC scenarios B1 and A1B suggests a significant increase of 7–15% for NC after 2040s due to the strengthened meridional winds, and a slight increase over the YRV due to less significant intensification of the Mei-yu front.     

Simulations of the effects of soil temperature and humidity disturbances on regional climate of China

Summary ?This simulation study was applied by a regional climate model (RegCM2) and forced by reasonable soil temperature and humidity disturbances, in order to examine the disastrous weather and climate-produced such disturbances that were performed in a series of experiments of different climatic zones, seasons and space/time scales, to recognize the persistence and to understand the mechanisms of their respective climatic responses under the current climatic background of China. The simulation results showed that, in regions of East Asian monsoon climate, the soil humidity disturbance (SHD) has greater impact on posterior climate responses than the temperature disturbance has. The SHD forcing exerts noticeable influence on rainfall generally. Although the centers of changed precipitation generally do not coincide with those of the disturbances, the centers are located mostly in downwind areas of the SHD core and in areas of prevailing updraft, even some places far away; with neighboring dry/moist SHD zones, a bigger rainfall increase tends to show up in the dry region instead of in the wet one. The simulation suggested that the SHD lasts for a rather long time, whose length is controlled by the presence of a positive feedback between the precipitation, the synchronous circulation patterns, the latitude and season, and the intensity of the SHD forcing. This study has found that the humidity disturbance (especially from rainfall) is in good correspondence to posterior temperature that the previous SHD enhancement leads to the subsequent temperature drop in the surface and near-surface layer, while the centers of lowered temperature can remain more than three months. Received April 3, 2001; Revised December 19, 2001     

水稻总叶龄模拟研究

以水稻的生物学特性为依据,利用田间试验实测资料,经过统计分析,确立了水稻总叶龄与环境变量之间的相关关系,建立了不同品种种水稻的总叶龄模拟模式,发现日长是影响水稻总叶龄的主要因素,其次是温度。     

南方夏季对流云降水回波特征分析

利用1988～2000年7～9月南昌、建阳、长沙三站探空资料及同期地面和500 hPa天气图与降雨量资料等,对照1988～2000年7～9月南昌(建阳、长沙713雷达站部分资料)"713"雷达站回波素描图进行统计分析,得出南方夏季对流云回波的顶高、强度、性质等参数变化规律与主要特征,从宏观上了解影响南方夏季对流云回波参数等特征量的变化规律,为南方各省人工影响天气作业提供科学依据.     

珠江三角洲都市群城市热岛效应初步研究

近十年来 ,珠江三角洲都市群热岛效应全面形成 ,年平均热岛强度由 1 983年前的 0 1℃上升到 1 993年的 0 5℃。珠江三角洲都市群热岛强度呈明显的季节变化和日变化 ,1 1月份热岛强度最强 ,4月份最弱 ,就年平均而言 ,夜间的热岛强度大于白天。珠江三角洲都市群热岛强度空间分布呈中间强周围弱的分布格局 ,与各地的经济活动密切相关 ,热岛强度强的地方均为广东经济活动最活跃的地区。     

气象短信业务营销策略的探讨

从气象信息传播的效果入手,阐述了气象短信在气象信息传播中的优势以及营销推广策略。     

广东省寒潮、强冷空气的气候特征及与ENSO的关系

本文对影响广东的寒潮、强冷空气与ENSO的关系进行了分析，结果表明：寒潮和强冷空气活动多的年份一般出现在中等或强的El Nina期间。寒潮和强冷空气活动少的年份容易出现在La Nina期间，而较难出现在El Nina期间。     

微服务在气象数据服务中的应用研究

在气象数据服务逐渐接口化背景下,MUSIC作为CIMISS气象数据接口服务的主要系统,得到了各级业务部门的广泛应用,但也存在不完善和使用难等问题。基于MUSIC以微服务架构设计与开发气象数据服务系统,扩充了MUSIC接口,实现了接口编制、编排和图形化使用,提升了接口使用人性化水平,增强了MUSIC业务支撑能力和业务适应性。