Assessment of storage lipid accumulation patterns in eucalanoid copepods from the eastern tropical Pacific Ocean

Members of the copepod family Eucalanidae are widely distributed throughout the world׳s oceans and have been noted for their accumulation of storage lipids in high- and low-latitude environments. However, little is known about the lipid composition of eucalanoid copepods in low-latitude environments. The purpose of this study was to examine fatty acid and alcohol profiles in the storage lipids (wax esters and triacylglycerols) of Eucalanus inermis, Rhincalanus rostrifrons, R. nasutus, Pareucalanus attenuatus, and Subeucalanus subtenuis, collected primarily in the eastern tropical north Pacific near the Tehuantepec Bowl and Costa Rica Dome regions, noted for its oxygen minimum zone, during fall 2007 and winter 2008/2009. Adult copepods and particulate material were collected in the upper 50 m and from 200 to 300 m in the upper oxycline. Lipid profiles of particulate matter were generated to help ascertain information on ecological strategies of these species and on differential accumulation of dietary and modified fatty acids in the wax ester and triacylglycerol storage lipid components of these copepods in relation to their vertical distributions around the oxygen minimum zone. Additional data on phospholipid fatty acid and sterol/fatty alcohol fractions were also generated to obtain a comprehensive lipid data set for each sample. Rhincalanus spp. accumulated relatively large amounts of storage lipids (31–80% of dry mass (DM)), while E. inermis had moderate amounts (2–9% DM), and P. attenuatus and S. subtenuis had low quantities of storage lipid (0–1% DM). E. inermis and S. subtenuis primarily accumulated triacylglycerols (>90% of storage lipids), while P. attenuatus and Rhincalanus spp. primarily accumulated wax esters (>84% of storage lipids). Based on previously generated molecular phylogenies of the Eucalanidae family, these results appear to support genetic predisposition as a major factor explaining why a given species accumulates primarily triacylglycerols or wax esters, and also potentially dictating major fatty acid and alcohol accumulation patterns within the more highly modified wax ester fraction. Comparisons of fatty acid profiles between triacylglycerol and wax ester components in copepods with that in available prey suggested that copepod triacylglycerols were more reflective of dietary fatty acids, while wax esters contained a higher proportion of modified or de novo synthesized forms. Sterols and phospholipid fatty acids were similar between species, confirming high levels of regulation within these components. Similarities between triacylglycerol fatty acid profiles of E. inermis collected in surface waters and at >200 m depth indicate little to no feeding during their ontogenetic migration to deeper, low-oxygen waters.     

夏季东半球热带海温异常对亚洲季风环流和降水影响的数值试验

利用一个全球大气环流谱模式，模拟了７月份大气对东半球热带海洋（阿拉伯海、孟加拉湾、南海、西太平洋）海温异常的响应。试验结果表明，热带海洋的热状况是影响亚洲季风环流和降水的一个重要因素。     

基于最大熵原理的黄土丘陵区地质灾害规模频率分布研究

在分析地质灾害规模分布的基础上,基于最大熵原理在理论上推导出崩塌、滑坡和不稳定斜坡灾害长、宽和厚等参数规模频率负指数分布关系,提出了规模参数频率分布简单而有效的计算公式。最后以黄土丘陵区宝塔区为例,对所提出的公式进行验证,结果表明：（1）宝塔区地质灾害以中型滑坡和中型崩塌为主,但大型地质灾害在控制着滑坡崩塌总面积和总体积中起着重要的作用;（2）滑坡、崩塌和不稳定斜坡规模等级指数主要集中于(5.5,6]级、(4,4.5]级和(5,5.5]级;（3）崩塌、滑坡和不稳定斜坡的长、宽和厚规模频率分布符合更简单的指数关系,且用指数关系拟合的规模频率曲线不会产生偏转效应;（4）对面积和体积取算术平方根和立方根后,它们的规模－频率分布也呈现出负指数分布,并且拟合效果良好（决定系数R2>0.9,概率P<0.05）。     

青藏高原地区过去2000年来的气候变化

依据冰芯、树轮、沉积物分析和冰川波动等各单点古气候代用资料,以及重建的综合温度变化曲线,分析了近 2000年青藏高原温度变化的整体性和区域性特征。全青藏高原综合温度曲线显示中世纪暖期（1150-1400年）、小冰期（1400-1900年）以及公元 3～5世纪冷期的存在。青藏高原温度变化具有明显的区域性特征。在 9～11世纪,青藏高原东北部以温暖为特征,而青藏高原南部和西部表现为寒冷。青藏高原南部和西部分别于1150-1400年（此时段在高原东北部表现为弱暖期）和1250-1500年经历了气候变暖。与中国东部文献记录的最新综合研究结果比较,高原东北部与中国东部的温度变化最为一致。而且,许多重大气候事件,如1100-1150年、1500-1550年、1650-1700年和1800-1850年的冷事件在高原和中国东部同时出现,而后 3次冷期与小冰期期间中国西部发生的冰川前进相匹配。     

Broad-scale spatial pattern of forest landscape types in the Guiana Shield

Detecting broad scale spatial patterns across the South American rainforest biome is still a major challenge. Although several countries do possess their own, more or less detailed land-cover map, these are based on classifications that appear largely discordant from a country to another. Up to now, continental scale remote sensing studies failed to fill this gap. They mostly result in crude representations of the rainforest biome as a single, uniform vegetation class, in contrast with open vegetations. A few studies identified broad scale spatial patterns, but only when they managed to map a particular forest characteristic such as biomass. The main objective of this study is to identify, characterize and map distinct forest landscape types within the evergreen lowland rainforest at the sub-continental scale of the Guiana Shield (north-east tropical South-America 10° North-2° South; 66° West-50° West). This study is based on the analysis of a 1-year daily data set (from January 1st to December 31st, 2000) from the VEGETATION sensor onboard the SPOT-4 satellite (1-km spatial resolution). We interpreted remotely sensed landscape classes (RSLC) from field and high resolution remote sensing data of 21 sites in French Guiana. We cross-analyzed remote sensing data, field observations and environmental data using multivariate analysis. We obtained 33 remotely sensed landscape classes (RSLC) among which five forest-RSLC representing 78% of the forested area. The latter were classified as different broad forest landscape types according to a gradient of canopy openness. Their mapping revealed a new and meaningful broad-scale spatial pattern of forest landscape types. At the scale of the Guiana Shield, we observed a spatial patterns similarity between climatic and forest landscape types. The two most open forest-RSLCs were observed mainly within the north-west to south-east dry belt. The three other forest-RSLCs were observed in wetter and less anthropized areas, particularly in the newly recognized “Guianan dense forest arch”. Better management and conservation policies, as well as improvement of biological and ecological knowledge, require accurate and stable representations of the geographical components of ecosystems. Our results represent a decisive step in this way for the Guiana Shield area and contribute to fill one of the major shortfall in the knowledge of tropical forests.     

Some Fundamental Problems of Geodynamics and Application of Earth Observations by Space-Based Measurements

Although great-progress has been made in the earth sciences,some fundamental problems of geodynamics remain unsolved.They are concerned with the whole earth as well as regional tectonics,such as the west Pacific and Qinghai-Xizhang plateau.The new generation of earth observation by space-based measurement will contribute to solving these problems of geodynamics.In this regard,some specific plans about application of these techniques are suggested in this paper.     

2006年超级台风“桑美”强度与结构变化的数值模拟研究

使用一个高分辨率、非静力数值模式WRF模式对2006年超级台风Saomei强度和结构进行了数值模拟研究.首先,评估了Makin的粗糙度长度公式对台风Saomei强度和结构变化的影响,结果表明,采用新参数后,使得模拟的台风强度变化与实况最佳路径资料的强度变化更一致,对超级台风Saomei强度预报有改进;但对台风路径的影响不大.通过QuikSCAT、雷达和TRMM非常规资料的验证,进一步表明模拟的台风Saomei的结构与实况很接近,可以再现台风内核区域的部分"双眼墙"和"Annular"结构.其次,通过对台风Saomei边界层过程模拟的改进,表明在平均风速大于40 m/s时边界层各物理量明显改善,使得模式最大强度比传统的简单外推插值方案有显著改进,特别是在台风最强阶段,当台风Saomei眼墙区域的海表面拖曳系数C_d的相对变小,使得其眼墙区域的平均切向风速、径向风速、垂直风速、温度距平、涡旋动能和绝对角动量等物理量均有增强.表明台风Saomei眼墙氏域(20-40 km)各物理量的贡献对其强度和结构变化的影响十分重要.最后,在此基础上进一步分析模式海温和大尺度环境垂直风切变对台风Saomei强度和结构变化的可能影响,讨论了台风Saomei在其增强和消弱阶段中,大尺度环境垂直风切变对其强度变化的负反馈作用.     

热带气旋路径动力释用预报的集合预报方案

考虑到热带气旋中心定位的不确定以及热带气旋（以下简称ＴＣ）路径动力释用预报对ＴＣ中心位置初值的敏感性,本文以ＴＣ路径动力释用预报方案为基础,应用集合预报原理构造了具有５０个成员的集合预报试验方案,经１９９７和１９９８年１５个ＴＣ的１１８次试验对比,结果表明,５０个成员的集合预报方案２的改进效果较好,其平均距离误差较业务预报的平均距离误差有较显著的减小。集合预报原理应用于ＴＣ路径动力释用预报的可行性     

西北太平洋热带气旋气候变化的若干研究进展

热带气旋气候变化研究不仅是当前国际热带气旋气候界的热点科学问题,而且也是具有现实意义的社会问题,各国气象学者和科学家们对此进行了广泛的研究。虽然热带气旋活动与气候变化之间的关系及其相应的内在物理机制至今还处在探究之中,但是近20多年来热带气旋气候学的研究还是取得了显著的进展。本文主要针对濒临中国的西北太平洋海域,回顾了热带气旋活动季节内、年际、年代际变化及其全球变暖背景下的变化趋势的气候学研究。此外,文中也对西北太平洋热带气旋气候学的研究进行了展望,并提出了该领域中一些亟待解决的科学问题。     

台风螺旋雨带——涡旋Rossby波

台风中的螺旋云雨带是由多种探测手段被观测到的现象,是为大家所共识的不争事实.但是,对它的形成、维持的理论解释,虽有多种学说,一直以来人们都倾向于重力惯性波说.而重力惯性波说有一个致命的弱点,即波的相速理论值为101m/s量级,它要比螺旋云雨带实测移速只有100m/s几乎大一个量级.于是从前几年开始,人们又回到30多年前提出的涡旋Rossby波说那里去寻找合适的解释.经典的Rossby波是β=(df/dy)作用的大尺度波动,而适用于台风中螺旋云雨带的涡旋——Rossby波乃是f平面(β=0)上的中尺度波动.那末,对这两类尺度不同和成波机理不同的波动,何以均冠予Rossby波一词?本文试图从动力学等价原理上,对此作统一联系的说明.其结果是:台风基本气流的涡度ζ随径向(r)变化的梯度dζ/dr=(1/r)(∂/∂r)(rvλ),在动力学上等价于科氏参数f随纬度变化的梯度即β=df/dy;或者说它们在绝对涡度守恒的前提下,作为波扰动的成波机理是等价的.