A Case Study Of An On-Ice Air Flow Over The Arctic Marginal Sea-Ice Zone

A case study of warm air advection over the Arctic marginalsea-ice zone is presented, based on aircraft observations with direct flux measurements carriedout in early spring, 1998. A shallow atmospheric boundary layer (ABL) was observed, which wasgradually cooling with distance downwind of the ice edge. This process was mainly connected with astrong stable stratification and downward turbulent heat fluxes of about 10–20 W m^-2, but wasalso due to radiative cooling. Two mesoscale models, one hydrostatic and the other non-hydrostatic,having different turbulence closures, were applied. Despite these fundamental differences betweenthe models, the results of both agreed well with the observed data. Various closure assumptions had amore crucial influence on the results than the differences between the models.Such an assumption was, for example,the parameterization of the surface roughness for momentum (z₀) and heat (z_T). This stronglyaffected the wind and temperature fields not only close to the surface but also within and abovethe temperature inversion layer. The best results were achieved using a formulation for z₀ that took intoaccount the form drag effect of sea-ice ridges together withz_T = 0.1z₀. The stability within theelevated inversion strongly depended on the minimum eddy diffusivity K_min. A simple ad hocparameterization seems applicable, where K_min is calculated as 0.005 timesthe neutral eddy diffusivity. Although the longwave radiative cooling was largest within the ABL, theapplication of a radiation scheme was less important there than above the ABL. This was related to theinteraction of the turbulent and radiative fluxes. To reproduce the strong inversion, it wasnecessary to use vertical and horizontal resolutions higher than those applied in most regional andlarge-scale atmospheric models.     

本世纪昆明气温异常及突变的分析

根据昆明１９２１～１９９３年的年，夏季（６～８月），冬季（１２～２月）平均气温资料，分析研究了昆明的气温变化趋势，冷暖阶段，气温异常发生频率及气温突变点，结果表明：从本世纪２０年代开始，昆明气温呈上升趋势，至４０年代前后达最高，此后下降，７０年代降至最低，８０年代开始略有回升，１９２１～１９５４年为偏暖阶段，１９５５～１９９３年偏冷阶段，昆明高温异常主要出现在１９５０年以前，低温异常大多数出现在１     

Roll Vortices and Boundary-Layer Development during a Cold Air Outbreak

The development of the boundary layer during a cold air outbreak in the FramStrait is documented by aircraft measurements. The convection was organisedinto roll vortices with aspect ratios increasing from 2.9 near the ice edgeto more than 6 at 100 km further downstream. This increase coincides with anincrease of the latent heat release in the cloud layer. The stability parameter-zi/L varies from about zero at the ice edge to 30 at a distance of 200 kmdownstream over open water where the satellite picture still shows cloudstreets. The increase is mainly due to the deepening of the boundary layer.The turbulent vertical sensible and latent heat fluxes near the surface amountto 400 W m^-2 within a 300 km off-ice zone. 25% of the upward heat fluxin the subcloud layer is carried out by organised roll motions. Experimentswith a 2-dimensional non-hydrostatic model show a similar roll aspect ratio inthe first 50 km, but further downstream where condensational heating is moreimportant the modelled roll wavelengths are distinctly smaller than the observedones.     

陕西洛南陶湾群三岔口组砾岩研究

陶湾群三岔口组砾岩是一套分布于华北地块南缘的水下碳酸盐岩型重力流沉积，砾岩的形成同商州铁炉子栾川断裂带早期活动性质存在因果关系。通过１∶５万区调填图发现，陶湾群三岔口组砾岩从母岩区到砾岩堆积区之间无断陷作用；沉积基底基本连续；砾岩沉积组构出现有序的横向变化规律，依次为母岩区层状白云岩（α区）、具有垂向张裂隙及流动构造的始滑区白云岩（β区）、具有节状构造的滑移区白云岩（γ区）和砾岩堆积区（δ区）。陶湾群三岔口组砾岩时代厘定为早寒武世晚期至中寒武世，这也是华北地块南缘盆地环境的主形成期，砾岩是在东秦岭洋向华     

福建省水系沉积物微量元素含量特征及成矿远景预测

根据区域化探水系沉积物测量分析３万余件样品中４０种元素含量，统计了３２种微量元素的背景平均值，浓度克拉克值，总体变化系数等参数。在利用水系沉积物富集系数估计值对浓度克拉克值进行校正后，使用顺序号累加法对福建省３２种元素内生成矿作用的规模进行预测排序，并分析了银，硼的资源潜力。     

跨孔条件下椭球模型的视电阻率异常特征

在跨孔条件下，利用积分方程法计算了孔区内外不同位置、不同产状的三维椭球体模型视电阻率异常。根据所得的典型数值模拟结果，借助视电阻率异常信息剖面图，对异常进行研究，总结了异常特征及其变化规律，并以此为基础分析和认识了其他模型的异常特征。     

中国古大陆及其边缘早古生代层序地层及海平面变化的基本特征

着重总结了我国古大陆及其边缘早古生代大层序（ｍｅｇａｓｅｑｕｅｎｃｅ，一级层序）和中层序（ｍｅｓｏｓｅｑｕｅｎｃｅ，二级层序），以及一级、二级海平面变化的基本特征，并与国外早古生代海平面变化进行对比．我国３大古陆（华北陆块、扬子陆块、塔里木陆块）及其边缘早古生代大层序可划分为两个（ＭＧ－１，ＭＧ－２）．中层序划分为５个（ＭＳ－１，ＭＳ－２，ＭＳ－３，ＭＳ－４，ＭＳ－５）．ＭＧ－１包括ＭＳ－１，ＭＳ－２和ＭＳ－３，时限为９４～１１２Ｍａ（寒武纪和早奥陶世），底以巨大不整合为界，顶以著名巨大沉没不整合为限，沉积了我国显生宙大部分的碳酸盐岩，赋存着丰富的油气和各种金属及非金属矿产．ＭＧ－２包括ＭＳ－４和ＭＳ－５，时限为５８～６８Ｍａ（中、晚奥陶世和志留纪），底界以巨大沉没不整合为界，为硅质碎屑－碳酸盐岩组合．海平面变化的级别划分对应于层序．中国３大古陆及其边缘早古生代海平面变化的总貌：ＭＧＳＣ－１初期普遍发生快速海进，海平面升高，尔后海平面下降，其间有多期次的小幅度海进和海退变化．ＭＧＳＣ－２则普遍海平面升高，上升幅度大于ＭＧＳＣ－１，尔后逐渐下降．     

克服低纬度化磁极困难的有效方法

低纬度地区（尤其是磁赤道附近）磁场化极是长期以来没有很好解决的问题。这里提出的方法只时常规化极稍加改进，通过时化极因子的频点偏移，避开无界点，使化极结果改善很大，甚至在赤道上也可以化极。它既有很高的精度，又因仍是在频率域内进行，故计算方便、快速，非常适合大面积的资料计算     

黔中三叠纪地层研究新进展

通过对黔中地区区域地质调查，在二叠系—三叠系过渡层中发现了一系列的韵律层，并通过岩性岩相、矿物学、地球化学和地层古生物学研究，认为过渡层中韵律层是远源火山碎屑重力流沉积产物，并据古生物、沉积学、地层学研究将过渡层归属于三叠系。原安顺组下部“大汪段”之上、下发现大量牙形刺化石，根据岩性及古生物特征，将“大汪段”归入大冶组。黔中—黔南中三叠统陆源碎屑体系的物源来自江南古陆；菊石、双壳类化石层是浊流作用形成的事件沉积层。     

Assessment of Lichen Vitality During a Transplantation Experiment to a Polluted Site

The present work evaluates the stress effects in two epiphytic lichen species with different thallus morphology, the foliose Parmelia caperata and the fruticose Evernia prunastri, as resulting from transplanting from an unpolluted to an air-polluted area. Lichen samples were collected in Portugal in a clean area, during the spring 2003, and transplanted (1) to the same zone nearby and (2) to a polluted area as affected by an industrial complex. Transplant samples were taken periodically during four months in both places. At the same time lichen samples from the clean-air site native (in-situ) populations were also collected. For each sample were measured the chlorophyll content, the chlorophyll degradation and the cell membrane damage, the latter represented by leacheate conductivity. During the experiment the meteorological conditions were registered. The results indicate the absence of stress effects of transplanting as such, and suggest that leachate conductivity may be the more sensitive indicator of general lichen vitality.