A literature review on trace metals and organic compounds of anthropogenic origin in the Wider Caribbean Region

About 30 studies from the published literature were reviewed to determine the pollution status regarding heavy metals and organic compounds of the Wider Caribbean Region (WCR). The literature revealed that most studies were performed in the South and Central American Caribbean Region with sparse reports on the small island states. Collectively, the most frequently analyzed heavy metals were Pb, Cu, Zn, Fe, Cd, Ni, Mn and Cr while DDT and its metabolites were the most frequently reported organic pollutants. The samples which were analyzed vary in terms of sampling schemes, parameters and analytical techniques, as well as differences in data reporting presentation (i.e. dry weight versus wet weight, sediment fraction analyzed, or % lipids). These differences make meaningful comparisons of the available data very difficult. Furthermore, there is limited data available for most of these contaminants from the majority of nations in the WCR. Therefore, any attempt to create a regional scale assessment from contaminants data available in the open literature is limited by the scarcity of available information.     

Sediment geochemistry in coastal maritime Antarctica (Admiralty Bay, King George Island): Evidence from rare earths and other elements

We report the concentrations of 22 elements in short coastal sediment cores of Admiralty Bay (King George Island, Antarctica) determined by Neutron Activation Analysis. We focus the discussion on rare earth elements (REE) because their fractionation patterns in sediments relative to local sources may offer insights about weathering, transportation, deposition, and diagenetic processes. We found strong correlations between REE and Th, indicating detrital origin. Despite strong Eh gradients, the Th-normalized redox-sensitive elements (e.g., Eu, Ce, Fe, As, and others) showed little variability within the sedimentary environment. The exceptions were U (depleted in the upper few centimeters) and Br (enriched in the upper few centimeters). While U appears to be removed from seawater via uptake across the boundary of reducing sediments, the mechanisms driving Br accumulation are unclear, but perhaps related to increasing diatom production driven by regional warming. A comparison with published concentrations from rocks representing the regional eroding units showed that the characteristics of source rock could be recognized in the REE fractionation patterns in our sediments. These results imply no significant alteration during weathering and sediment transport in the coastal region of Admiralty Bay and the prevalence of strong periglacial erosion in ice-free areas of maritime Antarctica in spite of the relatively mild regional environmental setting (e.g., high moisture and high temperatures).     

9. Life On Earth... And Elsewhere?

This concluding chapter is divided into two main parts. The first part is a summary of the main facts and events which constitute the present body of knowledge of the chronology of life in the solar system, in the form of “highlights” in astronomy, geology, chemistry and biology. The second part raises the interrogation “Is life universal?”, and tries to provide answers based on these facts and events. These answers turn out to differ widely among the various disciplines, depending on how far they feel able to extrapolate their current knowledge.     

“2011.6.18”湖北大暴雨成因分析

利用常规观测和地面自动站资料、NCEP1°×1°再分析资料、FY-2E卫星云图,以及武汉和荆州多普勒雷达资料,针对2011年6月17-18日湖北中东部地区一次大暴雨过程进行了天气动力学诊断和中尺度分析,结果表明:(1)暴雨是在有利的大尺度背景条件下,在特定的地域触发产生的,干冷、暖湿空气在江汉平原和鄂东剧烈交汇触发了这次大暴雨过程.(2)中尺度对流云团有3种类型:即单一云团型、合并型和急剧发展型.中尺度对流云团的大小与其生命史相关,尺度越大,生命史越长,在多个α中尺度对流云团之间的新生云团发展最为迅速,降水强度也最大.(3)呈气旋性转动的中尺度回波团和由低层较强的偏北风急流与偏南风急流辐合作用产生的中尺度复合体是此次暴雨过程雷达回波的主要表现形式;(4)地形对暴雨的强度以及落区等起到重要的作用,长江中游地区由于特定地形形成了三支明显的气流,由这三支气流组成的中尺度辐合系统促进了中尺度对流云团的形成和发展,云团F的加强和发展与地形作用密切相关.     

一次南海海雾微物理结构个例分析

本文利用2010年3月22～23日广东省湛江市一次海雾过程的雾滴谱和能见度资料,分析了海雾的微物理特征及微物理参量(数浓度、液态含水量和平均直径)之间的相关性,并讨论了影响海雾的主要物理过程。结果表明:湛江地区海雾的平均雾滴谱符合Junge分布;在海雾发展和成熟阶段,雾滴谱拓宽过程以及数浓度与平均直径的正相关关系表明本次海雾过程主要以雾滴活化和凝结增长过程为主;湍流过程的参与使得雾滴混合均匀,雾滴平均直径向3.5 μm附近集中,趋向平均化。同时湍流使雾体内部和外部空气交流,外部空气的凝结核核化,数浓度升高,凝结增长造成小雾滴变大。     

南京秋季辐射雾与平流雾边界层气象要素特征比较

利用南京市200 m气象铁塔的梯度观测资料、L波段探空雷达以及常规气象资料,对南京地区2010年两次秋季大雾天气过程进行了对比分析.结果表明:①两次大雾天气分别为典型的辐射雾和平流雾.②在两类大雾的发展过程中,对流层低层都存在较厚的逆温层,其中辐射雾存在多层辐射逆温和下沉逆温,而平流雾仅存在一层由暖平流形成的强逆温;边界层内辐射雾的贴地逆温强度明显强于平流雾,另外两次过程中均存在上层逆温.③雾的发展与地面气温的演变均有较好的对应关系:均是在地面气温出现突降、贴地逆温强度突增之后,边界层相对湿度随之显著上升,雾增强发展;辐射雾的雾顶高度远高于平流雾.④边界层风速呈现明显的峰值变化,且这种风速的脉动与雾的发展有一定的对应关系:当各层风速出现陡降后,雾增强发展,而后随着湍流的加强,雾趋于消散.     

Effects of Aerosols on Fogs Observed in the North China Plain

fog, microphysical properties, aerosol indirect effect, visibility     

2018年辽宁地区两次大雾天气成因分析

应用能见度观测仪、风廓线雷达、加密自动站和常规气象观测等资料,从天气学角度对2018年1月17—18日和11月24—25日辽宁地区两次大雾天气特点及边界层热动力条件对大雾形成的影响进行分析。结果表明：两次大雾天气表现与成因较为类似。大雾发展均有两个阶段,且天气背景条件相似。其中大雾第一阶段主要为辐射雾,辽宁中部位于弱辐合带上,大雾出现在偏南气流中,偏南风将海上水汽输送到营口—沈阳一带,辐射降温配合弱的上升冷却作用,形成近地面逆温,同时温度露点差减小、相对湿度增大,导致大雾爆发性发展。大雾第二阶段,在次日07—08时冷平流入侵近地面层,逆温层再次建立导致大雾发展,低层弱冷平流到达地面时间和位置是大雾精细化预报的关键因素。     

Assessment and characterization of heavy metal resistance in Palk Bay sediment bacteria

The present study aimed at characterizing the heavy metal resistance and assessing the resistance pattern to multiple heavy metals (300 mmol L?1) by Palk Bay sediment bacteria. From 46 isolates, 24 isolates showed resistance to more than eight heavy metals. Among the 24 isolates S8-06 (Bacillus arsenicus), S8-10 (Bacillus pumilus), S8-14 (B. arsenicus), S6-01 (Bacillus indicus), S6-04 (Bacillus clausii), SS-06 (Planococcus maritimus) and SS-08 (Staphylococcus pasteuri) exhibited high resistance against arsenic, mercury, cobalt, cadmium, lead and selenium. Plasmid curing confirmed that the heavy metal resistance in S8-10 is chromosomal borne. Upon treatment with the heavy metals, the strain S8-10 showed many morphological and physiological changes as shown by SEM, FTIR and AAS analysis. S8-10 removed 47% of cadmium and 96% of lead from the growth medium. The study suggests that sediment bacteria can be biological indicators of heavy metal contamination.     

大连低能见度气候特征及影响因素分析

利用美国国家气候数据中心NCDC提供的大连站1973-2010年间的每日地面观测概要数据统计分析了大连低能见度(＜4km)的年月分布、持续时间等特征,探讨了大连低能见度与天气现象、相对湿度、日平均风速等因素的关系.并利用韩国气象局KMA提供的2006-2010年每日天气图,对大连低能见度出现时的天气形势进行了归纳分析.