不同月海冰边界提取算法对南极海冰变化的影响分析

海冰与海水的交界地带是海-冰-气相互作用的重要区域,其变化会影响海洋生物栖息地的联通状态和海洋、大气的交换,确定海冰边界对于分析海冰动态变化具有重要意义[1-2]。被动微波传感器为长期监测海冰变化提供了大尺度的连续观测数据。从经典统计、随机集理论出发,应用三种由被动微波日均海冰密集度数据提取月均海冰边界的方法,分析三种月均边界的差异,以及不同月均边界提取方法对海冰长期变化分析的影响。     

长江三角洲地区大气气溶胶柱单次散射反照率特性研究

利用OMI卫星资料2006—2017年的483.5 nm波长的气溶胶柱单次散射反照率日均数据,分析了整层大气气溶胶单次散射反照率在长三角地区的时空分布特征,特别是其年际、月、季节变化特征.长江三角洲地区的大气气溶胶柱单次散射反照率越靠近海洋越大,而越靠近内陆越小.日均气溶胶柱单次散射反照率在0.881~0.971范围内变化,多年的平均值为0.939±0.024,最大分布概率出现在0.965~0.970区间,其值约为25％.长三角地区大气气溶胶柱单次散射反照率的年平均值集中于0.938~0.940之间,年际变化很小,变化值小于1％;月均柱单次散射反照率在6、8、9月有最大值,其值为0.968,而在2月有最小值,其值为0.915;季节平均单次散射反照率在夏季最大,其值为0.968,而在冬季最小,其值为0.919.     

江苏常州4.2级地震前的重力变化

利用江苏地区2019~2021年流动重力观测资料,分析江苏省常州市4.2级地震前不同时间尺度下的重力场变化。结果表明：1）0.5 a尺度重力场变化图像较好地反映了此次地震下降-转折上升-持续上升-反向变化及零值线附近发震的演化过程;2）常州4.2级地震前0.5 a和1 a尺度下的重力场均显示,地震发生在重力变化零值线附近。     

不同采样率下四分量钻孔应变观测同震变化特征

利用湟源台四分量钻孔应变观测的分钟值、1 sps、10 sps和100 sps四种不同采样率的观测数据,通过自检分析、同震应变阶分析和频谱分析等方法研究青海玛多M7.4地震同震变化特征。研究结果表明,分钟采样记录的地震波信息缺失严重,用分钟采样数据进行地震波初动、同震变化幅度等研究将会得到信度较低的结论;采样率越高,记录应变地震波信息的能力越强,但100 sps采样和10 sps采样结果相差不大,10 sps采样已能记录到比较全面的应变地震波信息;同震应变阶的变化性质和变化幅度与采样率无关;未来布设四分量钻孔应变仪时,建议应将采样率至少提高至1 sps。     

宽甸岩金预测区指示元素的优选

本文介绍了在宽甸无已知金矿床地区岩金预测工作中优选指示元素的思路。依据金矿地球化学理论,参考成矿带内已知金矿地球化学资料初选指示元素作为化学分析项目。化学分析结果出来后,编制地球化学图件时,考虑到减轻图幅负担和编图工作量,突出有用找矿信息,我们利用元素的变异性和致矿系数筛选出具有明显变异性和较高致矿性的元素,在此基础上利用元素间统计相关性和空间相关性,保留与成矿元素Au有明显相关性的元素,作为优选出的指示元素。     

禹城沙地水分动态规律及其影响因子

通过对禹城沙河地沙土土壤水分动态监测,分析其土壤水分剖面变化,得出本沙地土壤水分动态变化规律:依据降水、植被、地下水和土壤将土壤水分垂直剖面划分为表层0-10m或0-20cm干沙层,20-40cm土壤水分变化剧烈层,40-80cm土壤水分活跃层,80-120cm以下土壤水分深部稳定层;沙地土壤水分随季节变化划分为,春季水分变化较微──弱失水阶段,夏季水分剧烈变化──降水补给阶段,秋季水分变化缓慢——失水阶段,冬季水分变化较微弱──调整阶段。     

Seasonal Changes in the Biochemical Composition of the Edible Sea Urchin Paracentrotus lividus Echinodermata: Echinoidea in a Lagoonal Environment

Abstract. Monthly soluble and insoluble protein, carbohydrate, lipid and ash levels and energetic content were measured in tissues of Paracentrotus lividus adults living in a lagoonal environment over a 1-year period to increase our understanding of resource allocation to the different tissues. The biochemical composition of P. lividus individuals in this environment is similar to that observed in other environments. The gonad and gut contained a high level of proteins soluble or insoluble, a lesser amount of lipids and, finally, a low level of carbohydrates. The main component of the test was ash, followed by protein levels. The lipid and carbohydrate levels in the test were very low. Seasonal variability in the biochemical composition of the different body parts was observed. In the gonad, an increase in the level of lipids was recorded concomitant to an increase in gonad weight. The lipids and carbohydrates, after an initial increase, decreased with the maturation of the gonad. The biochemical variations observed in the gut seem to be linked to both the reproductive cycle and the sea urchin's trophic activity. Variability in the test was low and irregular for all of the observed biochemical components. As P. lividus is an important member of the benthic community in the Urbinu lagoon, this echinoid represents an important store of materials and energy within this lagoonal environment.     

Dynamics of DOC of euphotic layer in the Taiwan Strait——Diurnal variation of large range

ThisstudywassupportedbytheStateEducationalCommittee(SEC)ofChina.INTRODUCTIONThedissolvedorganiccarbon(DOC),ordissolvedorganicmatter(DOM),isoneofthemostimPortantorganiccarbonreservoiroftheworld,whichmayaffectthecontentofCO2intheatmospherewithatime-scaleof1OOO~1OOOOyears(Hedges,1992).Theratesofproduction,degradationortransPortationofDOCareseveralmaindynamicalparametersofDOCintheeu-photiclayer.Inthispaper,wefocusonthediurnalvariationsofDOCinordertoestimatetheseparameters.METso…     

Seasonal and interannual variations in the velocity field of the South China Sea

A three-dimensional numerical model is used to simulate sea level and velocity variations in the South China Sea for 1992–1995. The model is driven by daily wind and daily sea surface temperature fields derived from the NCEP/NCAR 40-year reanalysis project. The four-year model outputs are analyzed using time-domain Empirical Orthogonal Functions (EOF). Spatial and temporal variations of the first two modes from the simulation compare favorably with those derived from satellite altimetry. Mode 1, which is associated with a southern gyre, shows symmetric seasonal reversal. Mode 2, which contributes to a northern gyre, is responsible for the asymmetric seasonal and interannual variations. In winter, the southern and northern cyclonic gyres combine into a strong basin-wide cyclonic gyre. In summer, a cyclonic northern gyre and an anticyclonic southern gyre form a dipole with a jet leaving the coast of Vietnam. Interannual variations are particularly noticeable during El Niño. The winter gyre is generally weakened and confined to the southern basin, and the summer dipole structure does not form. Vertical motions weaken accordingly with the basin-wide circulation. Variations of the wind stress curl in the first two EOF modes coincide with those of the model-derived sea level and horizontal velocities. The mode 1 wind stress curl, significant in the southern basin, coincides with the reversal of the southern gyre. The mode 2 curl, large in the central basin, is responsible for the asymmetry in the winter and summer gyres. Lack of the mode 2 contribution during El Niño events weakens the circulation. The agreement indicates that changes in the wind stress curl contribute to the seasonal and interannual variations in the South China Sea.     

1961—2010年青海省霜冻灾害变化特征及风险区划

基于青海省历史日最低气温、青海省农作物种植总面积、农作物产量等要素,运用数理统计构建致灾因子危险性、暴露性和灾损敏感性指数,采用图表法和指数乘积法开展青海省霜冻灾害变化特征及风险区划。结果表明,青海省作物种植区均有霜冻灾害,中心集中在东部农业区的门源、大通、互助、湟源和湟中,柴达木盆地东部的德令哈、都兰和乌兰,以及贵南和共和等地;发生时段主要在4—9月,5月发生频率最高;年际间霜冻灾害呈波动增加趋势,但趋势不显著,年代际间霜冻灾害呈显著波动增加趋势;霜冻灾害高风险区主要分布在东北部的门源、互助、大通和祁连东部。