Review of Earth Critical Zone Research

Since the Earth Critical Zone put forward by National Research Council of America in 2001, it has got a lot of attention and some significant progresses have been made. This paper summarized those Earth Critical Zone projects and related research plans organized and implemented by the United States of America, Germany, Australia, France, China and the European Union, as well as main scientific problems and future development direction in the study of Earth Critical Zone. According to research status of China, the four main research contents should be strengthened including structure, formation and evolution mechanism of Earth Critical Zone, the coulpling interaction mechanism between migration and transformation of material and multi-processes, sevice function and evolution features of Earth Critical Zone and its support and effect on sustainable development, model simulation of process and system of Earth Critical Zone. In addition, our country should actively conduct cooperation and communication with the advanced countries, and enhance our involvement in international key research plans.     

夏季南海北部微型浮游动物群落

根据2014年8月至9月于珠江口至南海中部断面(18°00'~22°00'N,114°00'~116°00'E)的南海北部海域进行采样调查,并进行了微型浮游动物群落分析。共发现微型浮游动物142种,隶属于2门44属,其中砂壳纤毛虫28属78种,占所有发现物种数的54.93%;寡毛类纤毛虫14属59种,占所有发现物种数的41.55%。优势类群为:拟卡金斯急游虫(Strombidium paracalkinsi)、具沟急游虫(Strombidium sulcatum)、维尔伯特急游虫(Strombidium wilberti)和无节幼体(nauplii)。调查区微型浮游动物的丰度介于11.43~959.35 ind/L之间,平均值为264.99 ind/L。微型浮游动物垂直分布总体特点是密集区位于50 m水层,50 m水层之下丰度逐渐减少。表层微型浮游动物丰度高值区位于J5-I1站位之间。断面的香农-威纳指数范围在0.92~4.18之间,平均值为2.77;均匀度指数在0.63~1之间,平均值为0.87。应用典范对应分析(CCA)发现温度和盐度是影响微型浮游动物群落的重要因素。通过对连续追踪站位的调查发现,上层水体微型浮游动物群落丰度随着时间而发生一定的变化,下层水体相对较平缓。微型浮游动物昼夜的垂直丰度变化与叶绿素浓度昼夜变化大致相符。     

大连蜈蚣藻孢子发育及生活史的研究

在实验室条件下,对大连蜈蚣藻(Grateloupia dalianensis H.W.Wang et D.Zhao)的孢子早期发育、盘状体的形成和直立枝生长进行了详细研究,对其生活史进行了详细观察,并进行了温度和光照强度对孢子发育影响的研究。结果表明:(1)孢子发育类型为间接盘状体型;(2)生活史由雌、雄配子体、四分孢子体和果孢子体三相世代组成,配子体与孢子体形态相同,属于同型世代交替,与属模蜈蚣藻(G.filicina)一致;(3)温度对盘状体和直立枝生长均有影响,最适温度均为16℃;(4)光照强度对盘状体和直立枝生长均有影响,最适光照强度分别为7 500 lx和10 000 lx。     

Impacts of climate change on the hydrological cycle over France and associated uncertainties

This study deals with the evolution of the hydrological cycle over France during the 21st century. A large multi-member, multi-scenario, and multi-model ensemble of climate projections is downscaled with a new statistical method to drive a physically-based hydrological model with recent improvements. For a business-as-usual scenario, annual precipitation changes generally remain small, except over southern France, where decreases close to 20% are projected. Annual streamflows roughly decrease by 10% (±20%) on the Seine, by 20% (±20%) on the Loire, by 20% (±15%) on the Rhone and by 40% (±15%) on the Garonne. Attenuation measures, as implied by the other scenarios analyzed, lead to less severe changes. However, even with a scenario generally compatible with a limitation of global warming to two degrees, some notable impacts may still occur, with for example a decrease in summer river flows close to 25% for the Garonne.     

俯冲带碳酸盐化对深部碳循环的启示:以中国西南天山碳酸盐化云母片岩为例

俯冲带可将地球表层碳输送至深部地幔,同时也记录着俯冲板片来源碳质流体的迁移沉淀机制,对地球深部碳循环具有重大影响。近年来,俯冲带脱碳机制的研究表明流体溶解脱碳作用是冷的大洋俯冲板片释放COH流体的重要方式,而上覆板块(尤其地幔楔)则被认为是缓冲这些COH流体的重要场所,甚至是俯冲带CO_2的唯一"归宿"。事实上,俯冲带岩石本身的固碳能力却受到了忽视,而对俯冲带岩石捕获和固存CO_2(carbon capture and storage,CCS)能力的评估对全球碳通量的估算尤为重要。本文以中国西南天山高压-超高压变质带中碳酸盐化云母片岩为例,探讨俯冲带岩石的碳酸盐化对深部碳循环的影响。西南天山长阿吾子一带的碳酸盐化云母片岩记录了俯冲板片起源的碳质流体对俯冲带云母片岩的交代作用,地球化学特征表明蛇纹岩释放的富水流体溶解俯冲洋壳中的碳酸盐可能是产生COH流体的重要机制。基于碳质流体对多硅白云母(Si(a.p.f.u.)=3.58～3.73)的交代及相对高压的碳酸盐矿物(主要为白云石和菱镁矿)与金红石的共生,结合区域上碳酸盐化云母片岩与高压碳酸盐化蛇纹岩(HP-ophidolomite)的伴生,我们认为云母片岩的碳酸盐化作用可能发生在俯冲板片峰期稍后的高压折返阶段。俯冲带云母片岩的固碳作用表明除了上覆板块,俯冲带岩石本身对于碳质流体也具有很好的吸收能力。初步估算表明俯冲带云母片岩的碳酸盐化每年可固存至少2.46～6.68Mt/yr,约占俯冲板片每年进碳量的4%～17%。     

Water Cycle Analysis of Social and Economic System in Tarim River Basin

Water cycle includes natural water circulation and social economic system water cycle. The concept of virtual water provides a new method and means for studying social water circulation. This paper is based on the theory of water circulation in social and economic system, using input-output analysis method quantitatively describes the Tarim River basin of social water cycle paths and analysis of water resources management in Tarim River basin sustainable development process of the key issues. The results show that the main sectors of virtual water export in the Tarim River Basin are agriculture, petroleum, natural gas and food industry. Agricultural water accounts for more than 98% of total water consumption, most of which is transferred to the food and textile industries, and the food industry export water from the agricultural sector. Shandong Province is the largest virtual water transport area in the Tarim River Basin. The main sector of virtual water input in the Tarim River Basin is the metallurgical industry. Finally, in view of the problems arising from the inter-industrial and inter-regional social water circulation in the Tarim River basin, the paper puts forward the ways and strategies of regulating agricultural and industrial water use in the Tarim River Basin.     

IPCC AR6报告解读：气候系统对太阳辐射干预响应

IPCC第六次评估报告（AR6）第一工作组报告评估了太阳辐射干预（Solar radiation modification,SRM）对气候系统和碳循环的影响。在大幅度减排基础上,太阳辐射干预有潜力作为应对气候变化的备用措施。目前,对于太阳辐射干预气候影响的评估都是基于模式模拟结果。评估主要结论如下：太阳辐射干预可以在全球和区域尺度上抵消一部分温室气体增加造成的气候变化（高信度);但是太阳辐射干预无法在全球和区域尺度上完全抵消温室气体增加引起的气候变化（几乎确定);有可能通过适当的太阳辐射干预设计,同时实现多个温度变化减缓目标（中等信度);在高强度温室气体排放情景下,如果太阳辐射干预实施后突然终止,并且这种终止长时间持续,将会造成快速的气候变化（高信度);如果在减排和CO₂移除的情况下,太阳辐射干预的实施强度逐渐减小至零,将显著降低太阳辐射干预突然终止产生的快速气候变化风险（中等信度);太阳辐射干预会通过降温作用,促进陆地和海洋对大气CO₂的吸收（中等信度),但是太阳辐射干预无法缓解海洋酸化（高信度);太阳辐射干预对其他生物化学循环影响的不确定性大。由于对云-气溶胶-辐射过程的相互作用和微物理过程认知有限,目前对平流层气溶胶注入、海洋低云亮化、高层卷云变薄等太阳辐射干预方法的冷却潜力和气候效应的认知还有很大的不确定性。     

Validation for a tropical belt version of WRF: sensitivity tests on radiation and cumulus convection parameterizations

对基本气候态和降水日变化的分析是检验模式模拟性能、理解模式误差来源的重要手段。为了评估出对热带气候模拟效果较好的物理参数化方案组合,本文应用WRF带状区域模式,主要比较了四种积云对流参数化方案:NewTiedtke、Kain-Fritsch、newSAS、Tiedtke,和两种辐射参数化方案:RRTMG和CAM,对热带带状区域的气候模拟结果。研究表明:使用NewTiedtke积云对流参数化方案和RRTMG辐射方案的试验,表现出对气温、降水及降水日变化等综合性最好的模拟性能;NewTiedtke积云对流参数化方案能模拟出较好的降水空间分布和降水日变化位相分布特征;与RRTMG辐射方案相比,CAM辐射方案会使温度模拟偏低,特别是陆地上更明显,这种陆地上的冷偏差可能主要来源于Tmin的模拟偏冷。     

Preindustrial, historical, and fertilization simulations using a global ocean carbon model with new parameterizations of iron limitation, calcification, and N2 fixation

The Canadian Model of Ocean Carbon (CMOC) has been developed as part of a global coupled climate carbon model. In a stand-alone integration to preindustrial equilibrium, the model ecosystem and global ocean carbon cycle are in general agreement with estimates based on observations. CMOC reproduces global mean estimates and spatial distributions of various indicators of the strength of the biological pump; the spatial distribution of the air-sea exchange of CO₂ is consistent with present-day estimates. Agreement with the observed distribution of alkalinity is good, consistent with recent estimates of the mean rain ratio that are lower than historic estimates, and with calcification occurring primarily in the lower latitudes. With anthropogenic emissions and climate forcing from a 1850-2000 climate model simulation, anthropogenic CO₂ accumulates at a similar rate and with a similar spatial distribution as estimated from observations. A hypothetical scenario for complete elimination of iron limitation generates maximal rates of uptake of atmospheric CO₂ of less than 1 PgC y⁻¹, or about 11% of 2004 industrial emissions. Even a ‘perfect’ future of sustained fertilization would have a minor impact on atmospheric CO₂ growth. In the long term, the onset of fertilization causes the ocean to take up an additional 77 PgC after several thousand years, compared with about 84 PgC thought to have occurred during the transition into the last glacial maximum due to iron fertilization associated with increased dust deposition.     

Variations in the quantity and composition of seston from an estuary in southern Chile on different temporal scales

Estuaries are characterised by highly variable environmental conditions largely driven by tidal and atmospheric forces. This study investigates variation in the physical environment and the composition of the seston on various temporal scales in the Quempillén estuary, southern Chile. The water column was sampled throughout the tidal cycle at various times of the year. Total particulate matter, particulate inorganic matter, particulate organic matter, particle numbers, total particle volume, proximate biochemical composition and energy content of the seston, chlorophyll a and chloropigments were routinely measured. In each of the months in which sampling took place, two or three tidal cycles were examined. The information not only helps to explain the dynamics of the estuary, but is essential for an understanding of the physiology and ecology of the suspension-feeders which exploit the seston as a food source, the most dominant being the gastropod Crepipatella dilatata. Temperature and salinity were generally highest during summer, but seston quality, defined by energy content and biochemical composition (lipid, protein and carbohydrate) was higher at the end of winter and during spring. Chlorophyll a values were greatest in late spring (November). Many of the variables studied changed frequently according to the phase of the tidal cycle, and in several cases significant differences were observed among tidal cycles from the same month of the same year. In general the variables measured did not exhibit consistent patterns linked to the tidal cycle, possibly because any such patterns were masked by atmospheric conditions (wind and rain) that dominate the region and greatly influence the estuary. The quantity and quality of the seston available to suspension-feeders is largely determined by these atmospheric forces, which cause an influx of terrigenous material from adjacent areas and also resuspend bottom sediment. These effects are magnified by the shallowness of the estuary (<2 m depth). The food supply for C. dilatata and other suspension-feeders therefore varies on temporal scales varying from hourly (tidal cycle) to daily/weekly (atmospheric forces) to monthly (seasonal influences), but inhibition of feeding by low salinity sometimes limits the ability of C. dilatata to exploit fully the available organic matter.