Ranking the risk of CO2 emissions from seagrass soil carbon stocks under global change threats

Seagrass meadows are natural carbon storage hotspots at risk from global change threats, and their loss can result in the remineralization of soil carbon stocks and CO₂ emissions fueling climate change. Here we used expert elicitation and empirical evidence to assess the risk of CO₂ emissions from seagrass soils caused by multiple human-induced, biological and climate change threats. Judgments from 41 experts were synthesized into a seagrass CO₂ emission risk score based on vulnerability factors (i.e., spatial scale, frequency, magnitude, resistance and recovery) to seagrass soil organic carbon stocks. Experts perceived that climate change threats (e.g., gradual ocean warming and increased storminess) have the highest risk for CO₂ emissions at global spatial scales, while direct threats (i.e., dredging and building of a marina or jetty) have the largest CO₂ emission risks at local spatial scales. A review of existing peer-reviewed literature showed a scarcity of studies assessing CO₂ emissions following seagrass disturbance, but the limited empirical evidence partly confirmed the opinion of experts. The literature review indicated that direct and long-term disturbances have the greatest negative impact on soil carbon stocks per unit area, highlighting that immediate management actions after disturbances to recover the seagrass canopy can significantly reduce soil CO₂ emissions. We conclude that further empirical evidence assessing global change threats on the seagrass carbon sink capacity is required to aid broader uptake of seagrass into blue carbon policy frameworks. The preliminary findings from this study can be used to estimate the potential risk of CO₂ emissions from seagrass habitats under threat and guide nature-based solutions for climate change mitigation.     

COTREC方法在江西地区的应用和检验

基于江西及其周边地区的雷达组合反射率拼图,将二维Boussinesq(水平无辐散)质量连续方程约束至江西地区的TREC风场,得到改善后的TREC风场(COTREC风场),并基于COTREC风矢量开展了江西地区雷达回波的外推。个例分析表明,经过二维无辐散连续方程约束后,COTREC风中的噪声和不一致得到了显著的平滑,其风速水平梯度和风向切变都显著减小。基于COTREC风外推的雷达回波在形态上也得到了明显的改善,其外推回波中由风场的噪声或不一致引起的异常失真回波明显减少。为了进一步评估TREC和COTREC方法的外推表现,对2018年7月1—31日江西地区有明显降水的287个时次的雷达回波分别进行了1 h和2 h外推。结果表明:相对于TREC方法,COTREC方法在1 h和2 h的外推时间上均能改善外推回波的精度,其外推回波与实况的相关系数和TS评分均较TREC方法高。     

Public preferences for policy intervention to protect public health from maritime activities: A 14 European country study

Marine ecosystems provide a wide range of goods and services that directly and indirectly benefit economies and support human health and wellbeing. However, these ecosystems are vulnerable to anthropogenic influences such as climate change, pollution and habitat destruction. The European Union (EU) recognises the role of the blue economy in providing jobs and contributing to economic growth, with the EU Integrated Maritime Policy being a cross-sectoral framework within which maritime activities are managed and coordinated. Sustainability is a central tenet, ensuring that sectors such as aquaculture and offshore wind energy, which are earmarked for growth, must develop in ways that do not negatively impact the health of the marine environment. However, there is currently little consideration of how these activities might impact public health. The current research used survey data from 14 European countries to explore public perceptions of these issues, broadly focusing on 10 maritime activities, with a specific focus on five activities related to the EU’s 2012 Blue Growth Strategy. The respondents appreciated the interconnections between these maritime activities, environmental protection and public health, as well as the potential trade-offs. Preferences for policy intervention to protect public health from different activities were predicted by both marine contact (marine sector employment, recreational activities) and socio-demographic (political attitudes, gender, age) variables, potentially aiding future engagement and communication initiatives. Substantive differences observed across countries in terms of policy preferences for different activities, however, warn against generalising for the European population as a whole.     

电视天气预报演播室改建中的声学处理方法

通过对电视演播室声学原理的分析,提出了室内噪声和混响时间两个演播室声学质量的衡量指标,结合作者的实践经验,提出了演播室改建中的具体技术处理方法。     

雷电过程中大气电场信号处理方法探究

基于天津市蓟州区大气电场探测数据和闪电定位数据,利用功率谱分析、小波降噪和快速傅里叶变换等信号处理方法,分析了雷电天气过程中地面大气电场变化特征。结果表明,雷电过程中大气电场能量主要集中在低频部分,利用sym5小波函数进行7层或8层分解,提取的低频信号能够反映大气电场的主要变化特征。在首次闪电发生前1小时,大气电场的频谱幅值起伏变化明显,且远高于非雷电天气电场频谱幅值。通过欧氏距离判别法,判断大气电场频谱特征更接近雷电天气还是非雷电天气,可为雷电预报预警提供参考。     

Estimating the value of carbon sequestration ecosystem services in the Mediterranean Sea: An ecological economics approach

Ocean and marine ecosystems provide a range of valuable services to humans, including benefits such as carbon sequestration, whose economic value are as yet poorly understood. This paper presents a novel contribution to the valuation of carbon sequestration services in marine ecosystems with an application to the Mediterranean Sea. We combine a state-of-the-art biogeochemical model with various estimates of the social cost of carbon emissions to provide a spatially explicit characterization of the current flow of values that are attributable to the various sequestration processes, including the biological component. Using conservative estimates of the social cost of carbon, we evaluate the carbon sequestration value flows over the entire basin to range between 127 and 1722 million €/year. Values per unit area range from −135 to 1000 €/km² year, with the exclusive economic zone of some countries acting as net carbon sources. Whereas the contribution of physical processes can be either positive or negative, also depending on the properties of incoming Atlantic water, the contribution of biological processes to the marine “blue carbon” sequestration is always positive, and found to range between 100 to 1500 million €/year for the whole basin.     

一种天气雷达相噪异常检测分析方法

相位噪声是脉冲多普勒天气雷达系统的重要性能指标,直接反映雷达系统的相干性.为了透彻理解天气雷达相位噪声指标的物理意义,归纳了天气雷达相位噪声指标异常的排查分析方法,以指导天气雷达机务人员测试排查天气雷达相噪指标异常故障.在深入分析相位噪声物理意义的基础上,根据新一代多普勒天气雷达相噪指标的测试原理和方法,对可能影响雷达系统相位噪声的各种因素进行总结分析,提出了一种天气雷达相噪指标异常的排查分析方法,河源天气雷达相噪超标的故障排除案例证明了该方法的有效性.     

Notes from council

A wide set of size‐distribution models of haze and fog droplets expressed in terms of the modified gamma distribution function have been used for evaluating the proportionality coefficient b in the empirical relationship between visibility V and liquid water content LWC, that is V=b (LWC)‐ ^2/3, as proposed by Eldridge (1966). The evaluations of b turn out to be consistent with the values proposed in the literature and give evidence for its close dependence on the shape‐parameters of the droplet size distribution, especially as regards the mode radius and the width of the larger‐droplet wing. Three average relationship curves are proposed respectively for dense haze, “dry and cold” fog and “wet and warm” fog.

Corresponding to these cases, three correlation lines are presented between b and the ratio of the volume extinction coefficient at 3.70 μm wavelength to that at 0.55 μm, evaluated for the same uniform path in hazy and foggy atmospheres. Applied to measurements of infrared and visible transmission such correlation lines give the possibility of estimating the most proper value of b to be used in Eldridge's relationship for different atmospheric conditions.     

脉冲多普勒气象雷达发射机相位稳定性分析

简要介绍了低相位噪声多普勒天气雷达发射机的特点和组成,脉冲多普勒气象雷达对发射机相位稳定性的要求,发射机满足脉冲多普勒气象雷达的要求所面临的关键技术问题。为了改善相位噪声,在发射机中采用了全固态调制器、回扫充电技术、充电校平技术和同步交流方波稳流灯丝电源等技术。分析了发射机影响脉冲多普勒气象雷达检测性能的主要因素以及射频脉冲信号受寄生调制的影响而产生的边带相位噪声,发现在发射机射频信号中不需要的寄生调制和噪声是由一系列源产生的,影响脉冲多普勒气象雷达相位稳定性的主要因素有射频激励源、电源纹波、脉冲时间抖动、幅度调制、颤噪效应、电磁感应和电磁干扰辐射源等。这些不需要的边带噪声限制了脉冲多普勒气象雷达在杂波中探测目标的能力。     

Investigation of Biosorption Behavior of Methylene Blue on Pleurotus ostreatus (Jacq.) P. Kumm.

The effect of varying parameters such as dye concentration, adsorbent dose, pH and temperature on the adsorption capacity of Pleurotus ostreatus is investigated. The commonly available white rot fungus Pleurotus ostreatus is investigated as a viable biomaterial for the biological treatment of synthetic basic methylene blue effluents. The results obtained from the batch experiments reveal the ability of the fungus to remove methylene blue. The performance is dependent on the dye concentration, pH, and fungal biomass. The equilibrium and kinetics of adsorption are investigated and the Langmuir equation is used to fit the equilibrium isotherm. The adsorption isotherm of methylene blue follows only the Langmuir model with a correlation coefficient of ca. 0.96–0.99. The maximum adsorption capacity is ca. 70 mg of dye per g of dry fungus at pH 11, 70 mg L^–1 dye, and 0.1 g L^–1 fungus concentration, respectively. This study demonstrates that the fungus could be used as an effective biosorbent for the treatment of dye‐containing wastewater streams.