Dynamic features of near-inertial oscillations in the Northwestern Pacific derived from mooring observations from 2015 to 2018

Near-inertial oscillation is an important physical process transferring surface wind energy into deep ocean.We investigated the near-inertial kinetic energy(NIKE) variability using acoustic Doppler current profiler measurements from a mooring array deployed in the tropical western Pacific Ocean along130°E at 8.5°N,11°N,12.6°N,15°N,and 17.5°N from September 2015 to January 2018.Spatial features,decay timescales,and significant seasonal variability of the observed NIKE were described.At the mooring sites of 17.5°N,15°N,and 12.6°N,the NIKE peaks occurred in boreal autumn and the NIKE troughs were observed in boreal spring.By contrast,the NIKE at 11°N and 8.5°N showed peaks in winter and troughs in summer.Tropical cyclones and strong wind events played an important role in the emergence of high-NIKE events and explained the seasonality and latitudinal characteristics of the observed NIKE.     

某铝土矿低空无人机遥感测绘成果精度分析

对于分布散、范围大的铝土矿区,传统测量手段及时获取满足精度要求的矿区测绘资料具有一定难度。采用低空无人机遥感技术,能够快速提供矿山建设所需要的数字线划图、数字高程模型及数字正射影像,实现矿山的数字化与信息化建设。结合某铝土矿测绘面积大、矿区地物要素较少的测绘特征,通过无人机影像快速空三加密以及DLG,DEM,DOM的制作技术,获得低空无人机遥感测绘成果。通过对解析空三加密点精度分析和GPS实测点检查,表明测绘成果满足1∶2 000测图精度要求。     

两种不同的SVM建模方法在大坝变形预测中的应用

用支持向量机对大坝变形监测数据建模分析和预测一般有两种方法:一是仅用大坝的变形数据作为输入端和输出端,构建支持向量机模型;二是用温度、水压等大坝变形的影响因子作为输入端,大坝变形数据作为输出端,构建支持向量机模型。两种建模方法比较研究鲜有讨论,文中用这两种建模方法对福建省某一大坝进行建模预测。结果表明,第二种方法建模预测速度更快,预测精度更高。     

一次冰雹天气过程的多源资料观测分析

利用地基微波辐射计、风廓线雷达和雨滴谱仪等观测资料,对2015年4月28日发生在南京的一次冰雹天气进行了分析,探讨新型探测资料在冰雹监测预警中的应用。结果表明:(1)华北冷涡后部冷空气南下,与低层暖湿气流交汇,是产生这次冰雹的天气背景;高空冷平流叠加在低层暖湿气流之上,使得对流层中低层形成不稳定层结;地面辐合中心及辐合线是降雹的触发机制。(2)微波辐射计监测显示,降雹期间冰雹云中上升气流将底层空气的感热和潜热向上输送,导致2 km以上大气有明显升温,由于低层水汽聚集及冰雹在近地层融化造成降雹时近地层相对湿度、水汽密度增大。冰雹发生在云液态水含量快速增长的波峰上,对冰雹的发生具有较好指示意义。(3)对比南京3站风廓线雷达资料表明各站上空环境风场存在一定差异,六合地区降雹前6 km高度高空急流有利于六合上空形成有利的辐散形势,降雹时0~6 km存在较深厚的垂直风切变,配合地面中尺度低压,降雹最为强烈;南京站降雹时,对流层中下层有一槽过境,而高淳地区冰雹由近地面垂直风切变激发。(4)六合站、高淳站雨滴谱仪分析表明不同降水相态对应的滴谱特征有差异,两站雨滴谱型分别呈指数型、多峰型分布。高淳站雨滴谱仪监测到直径达到15 mm的冰雹粒子,六合站冰雹直径最大为5 mm。两站速度谱大致为单峰型,在较强降水时刻,粒子下落峰值速度在3~4 m·~(-1)。(5)影响六合的超级单体存在钩状回波、回波悬垂、三体散射等雷达回波中尺度特征,地面中尺度低压系统、中低层的中气旋及高层的辐散环流配置造成了雹云中维持较强的旋转上升气流,有利于出现大冰雹。     

变质流体作用的元素地球化学研究

变质流体作用是变质岩－流体体系的重要地质作用过程，可以通过有效的地质地球化学方法揭示，综述了变质流体作用的地球化学研究进展，主要包括：流体包裹体，同位素和元素地球化学等方面，强调了元素地球化学研究对于示踪变质流体作用过程的重要性。     

金刚石包裹体中的古地幔信息

金刚石在地幔环境生长过程中会捕获一些包裹体，这些包裹体能够被金刚石携带到地球表层，金刚石包裹体保存有其生长时古地幔环境的信息，通过对这些包裹体的研究，,可以获取古地幔环境的信息，阐述了金铡石包裹体的特征，综述了金刚石包裹体在获取古地幔物理化学环境，相环境以及地幔信息方面的取得的一些成果。     

Ecological Footprint Evaluation of Three Types of Wood Flooring in China based on Their Production Data from 2000 to 2018

To encourage the environmental responsibility of consumers and manufacturers for forest management, it is necessary to evaluate the environmental influences of forest products. Ecological footprint (EF) is an internationally recognized indicator for estimating the natural capital consumption and environmental influences of various forest products. In this study, we developed an accounting model for the EF evaluation of wood flooring, which is a tertiary forest product, by the method of transformation. Next, we used that model to evaluate the EF of three types of wood flooring in China according to their production data from 2000 to 2018. We collected the necessary data by visiting typical enterprises in China and referring to the relevant literature. According to our results, the average EFs of solid wood flooring, engineered solid wood flooring and laminate flooring between 2000 to 2018 were 3.13×10 ⁶, 1.05×10 ⁷ and 5.07×10 ⁶gha, respectively. The total EFs of solid wood flooring, engineered solid wood flooring and laminate flooring from 2000 to 2018 were 5.95×10 ⁷, 1.99×10 ⁸and 9.64×10 ⁷gha, respectively. The coefficients of variation (CV) of the EFs for these three types of wood flooring were 0.45, 0.87 and 0.76, respectively. The average and total EFs of the engineered solid wood flooring were the largest among the three types of wood flooring. The per capita EF and unit EF for the engineered solid wood flooring were also the highest among the three types of wood flooring. The EFs showed an upward trend with irregular fluctuations from 2000 to 2018 for all three types of wood flooring. It is necessary to reduce the EF of the engineered solid wood flooring and use more environmentally friendly products, such as solid wood flooring, for environmental protection.     

低空急流识别及急流轴自动绘制方法研究

低空急流对强对流天气的预报有重要意义。针对目前低空急流主要由手工绘制,存在效率低、易受主观因素影响的问题,本文基于MICAPS高空全要素填图数据中的探空站风场信息,提出了一种低空急流自动识别及急流轴自动绘制算法。算法从急流轴定义出发,依次从风速、风向、探空站分布、中轴线位置等多个角度对低空急流轴进行检测。经过传递闭包聚类、急流轴关键点提取、不同风向急流轴关键点归并、急流轴平滑等步骤,实现了低空急流自动识别及急流轴的自动绘制。测试表明,在识别的基础上自动绘制的急流轴具有位置准确、形态自然、能完整反映急流水汽输送路径、适应复杂环境低空急流等特点。在291组测试数据中未发现空报,准确击中率达到94.96%。     

2021-04-16河北滦州MS4.3地震前的大气电场异常信号分析

中国科学院国家空间科学中心分布在天津市宝坻区和廊坊市永清县的2个观测台站在2021-04-16河北滦州M_S4.3地震前均观测到大气电场异常。宝坻站监测到过境云与地质活动混合型电场异常信号;永清站监测到湾型持续电场异常信号,属于典型的临震前小时尺度先兆信号,其幅度和持续时间均明显高于宝坻站的异常电场信号。对比电场异常期间2个台站的气象活动和空间天气活动发现,虽然2台站电场异常信号的表现方式不同,但背景变化中均隐含大型地质活动信号。分析结果表明,未来可通过分析多源活动导致的空间静电演变过程,形成有效的识别方法,在一定的气象活动范围内,从大气静电监测数据中提取中等以上强度地震的前兆信息。     

基于GPT3模型的ZTD及PWV反演精度分析

使用亚洲区域18个IGS测站和中国区域内16个探空站2016~2018年的数据,研究GPT3模型反演天顶对流层延迟（ZTD）和大气可降水量（PWV）的精度,并与其他GPT系列模型进行对比。结果表明,GPT3-1模型估计的ZTD的bias均值和最大值均最小,分别为1.34 mm和14.06 mm;GPT3模型整体精度略优于GPT2w模型,优于GPT2模型。探空站处GPT3模型反演的PWV的bias和RMSE均表现出较强的季节性特征;由GPT3模型反演的PWV的月均值可知,GPT3-1模型比GPT3-5模型具有更高的精度和稳定性。