Continuous Observation System Research Articles

Continuous Measurement and Molecular Compositions of Atmospheric Water‐Soluble Brown Carbon in the Nearshore Marine Boundary Layer of Northern China: Secondary Formation and Influencing Factors

AbstractUnderstanding the evolution of brown carbon (BrC) in the atmosphere is essential for investigating its climate effects. This study deployed a novel in‐situ BrC continuous observation system to firstly measure water‐soluble BrC absorption (AbsWS‐BrC) in an offshore island over the Bohai Sea in the winter of 2020. The AbsWS‐BrC abundance before the cold wave (BCW) was more than twice higher than that after the cold wave (ACW). This was mainly ascribed to the substantially suppressed formation of secondary WS‐BrC (WS‐BrCsec). Diurnal patterns of AbsWS‐BrC exhibited nighttime peaks, which derived from enhanced primary emissions and strong aqueous‐phase processes. Photochemical processes bleached daytime WS‐BrC during BCW, while daytime peaks of WS‐BrCsec emerged during ACW due to the weakened photobleaching effect. Statistical analysis indicated ambient temperature and relative humidity as well as total oxidized nitrogen (NO2 + NO3−) and reduced nitrogen (NH4+ + NH3) were the dominant factors promoting WS‐BrCsec. Moderate aerosol pH (>2.5) also facilitated the formation of WS‐BrCsec while no obvious dependences of WS‐BrCsec on gas‐particle partitioning of ammonia, O3, and sulfur precursors were found. At the molecular level, BrC chromophores with the identified compositions, carbon oxidation state, O/C, H/C, and absorption spectra were compared between the two periods. Characteristics of water‐soluble CHO‐ and CHON‐BrC were more of secondary origin during BCW, while primary emissions contributed significantly to BrC chromophores during ACW. This study highlights the advantage of high resolution BrC measurement in probing its dynamic evolution and influencing factors.

Time Delay Correction for the MARCOS Lightning VHF Mapping Array System

In practical applications, system time delay (STD) of a VHF lightning mapping system, resulting from system manufacturing, installation, site differences, and signal channel inconsistency etc., is unavoidable and will affect the localization accuracy of the direction finding algorithm. In this article, a multiantenna VHF radiation continuous observation system (MARCOS) consisting of 7 channels is used as an example to make a quantitative analysis for the relationship between STD and localization error. The array is in an “L” shape, with a 9 m baseline. And its STD is obtained through actual measurement, using sweep-frequency method. The analysis results show that STD reduces the localization accuracy significantly. Especially, emissions with lower elevation are more vulnerable to STD. In order to correct localization error caused by STD, we utilize the actual measured STD of MARCOS to correct the error during the implementation of the algorithm. Field experiments are designed to verify the effectiveness of this correction method, with an unmanned aerial vehicle (UAV) and a portable radiation source. For MARCOS used in this article, the UAV experimental results show that the error caused by STD exceeds at least 2°, and even worse for the low elevation. However, after the STD is compensated, the localization error is alleviated within 1°. Finally, STD correction is applied to a triggered lightning data. Comparisons and analyses of the results are presented before and after STD compensation.

An IoT Based System for Monitoring the Environment

Air pollution is one of the biggest challenges of our daily lives. It affects human well-being by hypersensitivity and other pulmonary infections, which can lead to death. The growth of industries and automobiles donates more to air emissions. Natural air is important for all humans, and various developments have been used to constantly check air quality. This role offers a kind of continuous observation system for atmospheric emissions where the grouping of large poisonous gases into the air is detected using cost efficient sensors. This system shows the air quality reliably in a cloud by using an Internet of Things (IoT) scene, which is efficiently experienced from our PC or PDA. Nevertheless, the system includes an arrangement to store previously estimated details. This helps experts to study the air existence of the territory they are searching for a while for important purposes. Likewise, the frame identifies air quality and sends signals to the partners when the assessment of pollutants rises above a specified amount. In addition, it can be well implemented everywhere to check air quality in a smart smaller plan.

Variations in Soil Water Content and Evapotranspiration in Relation to Precipitation Pulses within Desert Steppe in Inner Mongolia, China

Neither single nor discontinuous hydrological observation data can truly reflect periodic changes in soil moisture under natural conditions or interrelationships between various water sources. Therefore, in this study, precipitation pulse characteristics and variations in the soil water content (SWC) and actual evapotranspiration (ETa) in relation to pulses are explored through a field multi-water continuous observation system set in desert steppe in Inner Mongolia, China. A comparison between precipitation events in the growing seasons of 2016 and 2017 shows that precipitation events that are greater than 10 mm are the main cause of dramatic interannual precipitation variations in this region. A single small precipitation event has a limited impact on SWC and provides no obvious increase in the SWC within the top 10 cm soil layer. The precipitation interval ratio (P/I) is suitable for comparing water stresses of different drying-wetting cycles, and correlations between soil layers are found to be closer in humid years than in dry years. In this study, three modes of interpulse ETa in the desert steppe are discussed: a stable ETa mode under a water-sufficient condition, an attenuation ETa mode, and a stable ETa mode under extreme drought conditions.

Broadband very high frequency localization of lightning radiation sources based on orthogonal propagator method

Broadband very-high frequency (VHF) localization of lightning radiation sources provides an important means for understanding lightning discharge characteristics and the corresponding physical mechanisms. In order to improve the ability to locate weak radiation sources, the orthogonal propagator method (OPM) is proposed to map the space-time evolution process of lightning discharge channels based on the theory of spatial spectrum estimation. In the method, the linear decomposition of the covariance matrix is used to form the orthogonal propagator, and the spatial spectrum is constructed according to orthogonality of subspaces. Then, the location of lightning radiation sources is determined by searching for the maximum of the spatial spectrum. For broadband VHF signals, the non-coherent subspace method is used to average the effective frequency points in bandwidth to reduce noise interference. Based on a multiple-antenna radiation continuous observation system (MARCOS), locating performance of the method is analyzed by numerical simulation. The method is verified by parameters such as locating error, half-peak width of the spatial spectrum, and angular resolution. Compared with the results from the time reversal technique(FDTR), the location error and recognition probability under a low signal to noise ratio (SNR) of the proposed OPM algorithm are similar to those of FDTR algorithm, but the angular resolution for two radiation sources of OPM algorithm is better than that of FDTR algorithm. Finally, the proposed method is used to map the spatial and temporal development of a classical triggered lightning discharge channels in the summer of 2017. The results show that the proposed method can clearly depict the basic structure of lightning discharge channels with high spatial and temporal resolution. For the upward positive leader of the triggered lightning, the OPM algorithm can locate more radiation sources with a better structure than the FDTR algorithm. It implies that the proposed OPM algorithm is better for locating weak radiation sources than the FDTR algorithm. Meanwhile, the OPM algorithm has better performance for resolving two radiation sources in the same window than the FDTR algorithm. As a result, the proposed OPM method is of great significance for improving the application value of broadband VHF arrays in the study of locating weak radiation sources and lightning initiation mechanisms.

Observed Variation of Three‐Dimensional Return Stroke Speeds Along the Channel in Rocket‐Triggered Lightning

AbstractAn improved very high frequency location system, multiple antenna radiation continuous observation system (MARCOS), is combined with high‐speed video observation to explore radiation source evolution during return stroke (RS) stages in triggered lightning. A three‐dimensional (3‐D) channel reconstruction is performed for speed measurement of the RS processes. The 3‐D average speeds for the two selected strokes (RS1 and RS3) over the bottom channel within 1 km are 9.24 × 107 m/s and 1.07 × 108 m/s, respectively. The high temporal‐spatial resolution of MARCOS permits thorough examination of the speed variation. Our observation shows that the 3‐D RS speeds of both RS1 and RS3 are increased initially with height for the first several hundred meters, maximized, and then decreased with height. To the best of our knowledge, this is the first evidence regarding nonmonotonic 3‐D RS speed variation in triggered lightning.

영재 개별화 교육에 관한 과학영재 지도교사들의 인식

이 연구의 목적은 과학영재를 위한 개별화 교육과정 및 프로그램의 필요성에 관해 과학영재교육 담당 교사들은 어느 정도 인식하고 있는지를 과학영재 교육기관의 현실에 비추어 심층적으로 탐색하여 문제점들을 짚어보고, 이를 기반으로 하여 앞으로 보다 적극적인 과학영재 개별화 교육과정 및 프로그램의 적용 가능한 방향에 관해 시사점을 도출하는 것이다. 연구 참여자는 과학영재를 지도한 경험이 있고, 영재교육 혹은 과학교과교육 분야로 학위를 가지고 있는 현직 교사를 중심으로 15명을 섭외하여 심층 면담하였다. 연구 결과, 연구 참여자 대부분은 과학영재교육에 있어 이상적인 영재교육은 학생의 성향에 따른 개인적 요구를 이해해야 하고, 학생이 스스로 주도하는 연구방향이어야 한다는 내용으로 개별화 교육의 필요성을 인식하고 있었다. 과학영재 개별화 교육과 관련한 과학영재교육 기관 운영의 문제점으로 교사들은 재정적 지원의 감소를 가장 큰 문제로 들었으며, 교사의 소명의식 및 전문성이 매우 중요한 요소로 언급되었다. 시간, 장소의 제약과 함께 대학입시와 관련된 교육환경의 영향도 무시할 수 없다는 의견이 많았다. 영재교육기관 및 대상자의 과도한 확대와 표준화 된 측정 도구 및 프로그램이 없다는 것, 교사의 일관된 관찰 시스템이 부족하다는 의견도 많았다. 또한, 영재교육기관들의 획일화된 교육과정이 문제점으로 지적되었고, 이미 진행되고 있는 개별화 교육프로그램도 단점이 많고 미미하게 진행되고 있음을 지적하였다. 이에 따라 앞으로 과학영재 개별화 교육을 적용하기 위한 방향으로 교사들은 최적화 된 교육환경과 일관된 정책적 지원을 요구하였으며, 교사의 지속적 관찰이 가능한 시스템이 필요하다는 의견을 피력하였다. 또, 학생 요구에 부합하는 교육과정과 프로그램이 가장 우선시 되어야하며, 협동학습 내에서의 동료학습이 개별화 교육의 대안이 될 수 있다는 응답도 있었다. 이와 함께 개별화 교육에 따른 열등감을 극복하기 위한 처치가 뒤 따라야 한다는 의견도 많았다. The purpose of this study is to figure out how much gifted science education teachers in charge of the class realize the necessity of individualized curriculum and program for scientifically gifted, to find out the problems of the gifted science educational institutions from exploring them in depth in the light of the reality in the gifted science educational institutions, and to draw implications about the applicable direction of more aggressive individualized curriculum and program for scientifically gifted. I chose 15 people with the incumbent teachers who have ever taught scientifically gifted and have a degree in the gifted education or science subject education as study participants and had a depth interview with them. According to result of the study, 14 of 15 study participants recognized the necessity of individualized education in science should understand the personal requirements according to the tendency of the gifted students and should be a study led by students themselves. Of the problems in gifted science education, teachers regarded the reduction in the financial support as the biggest problem and the vocation and professionalism of teachers were referred as a very important factor. With constraints of time and space, there were plenty of opinions that can't ignore the influence of educational environment associated with the university entrance examination. There were many opinions that there is excessive expansion of the agencies and the target for gifted students, no standardized measurement tools and programs and the lack of the system for the coherent observation as a teacher. Also, the unified curriculum of gifted science education institutions were pointed out as the problem and the individualized programs which were already under way have a lot of weakness and being offered marginally. Thus, from now on, to apply for individualized education of gifted science, teachers demanded optimized education conditions and consistent policy support, and expressed the opinion that there needs of a possible continuous observation system. Besides, the curriculum and programs matched the needs of the students should be taken priority the most, and there were another answers that fellow learning within the cooperative learning can be an alternative of the individualized. Along with that, there were lots of opinions that the treatment to overcome an inferiority complex according to the individualized should be followed.

An Automated Comparative Observation System for Sun-Induced Chlorophyll Fluorescence of Vegetation Canopies.

Detecting sun-induced chlorophyll fluorescence (SIF) offers a new approach for remote sensing photosynthesis. However, to analyse the response characteristics of SIF under different stress states, a long-term time-series comparative observation of vegetation under different stress states must be carried out at the canopy scale, such that the similarities and differences in SIF change law can be summarized under different time scales. A continuous comparative observation system for vegetation canopy SIF is designed in this study. The system, which is based on a high-resolution spectrometer and an optical multiplexer, can achieve comparative observation of multiple targets. To simultaneously measure the commonly used vegetation index and SIF in the O2-A and O2-B atmospheric absorption bands, the following parameters are used: a spectral range of 475.9 to 862.2 nm, a spectral resolution of approximately 0.9 nm, a spectral sampling interval of approximately 0.4 nm, and the signal-to-noise ratio (SNR) can be as high as 1000:1. To obtain data for both the upward radiance of the vegetation canopy and downward irradiance data with a high SNR in relatively short time intervals, the single-step integration time optimization algorithm is proposed. To optimize the extraction accuracy of SIF, the FluorMOD model is used to simulate sets of data according to the spectral resolution, spectral sampling interval and SNR of the spectrometer in this continuous observation system. These data sets are used to determine the best parameters of Fraunhofer Line Depth (FLD), Three FLD (3FLD) and the spectral fitting method (SFM), and 3FLD and SFM are confirmed to be suitable for extracting SIF from the spectral measurements. This system has been used to observe the SIF values in O2-A and O2-B absorption bands and some commonly used vegetation index from sweet potato and bare land, the result of which shows: (1) the daily variation trend of SIF value of sweet potato leaves is basically same as that of photosynthetically active radiation (PAR); and (2) the bare land is a non-fluorescent emitter, the SIF of which is significantly smaller than that of sweet potato; and (3) analysis result based on the measured data is basically same as that based on simulated data. The above results verified the reliability of the SIF extracted from the measured data and the feasibility of comparatively observing the SIF value and the commonly used vegetation index of multiple vegetation canopy with this continuous observation system. This approach is beneficial for comprehensively analysing the stress response characteristics of vegetation canopies.

Wide-area land subsidence caused by “the 2011 Off the Pacific Coast of Tohoku Earthquake”

This paper gives an overview of the crustal deformation caused by “the 2011 off the Pacific Coast of Tohoku Earthquake” (hereinafter: “the Tohoku Earthquake”) as detected by the GPS Earth Observation Network (GEONET), a GPS continuous observation system operated by the Geospatial Information Authority of Japan (GSI), and of ground deformation resulting from liquefaction triggered by the earthquake motion as determined by a leveling survey. A very large part of the Japanese archipelago was affected by the crustal deformation caused by the mainshock. The subsidence in the Pacific coastal area of the Tohoku region is especially remarkable. Based on a resurvey after the earthquake, the GSI revised the coordinates and heights of survey marks, including the Origin of the Japanese Horizontal Control Network and the Origin of the Japanese Vertical Control Network. We estimated the geometry of the seismogenic fault of the Tohoku Earthquake, as well as a slip model for the boundary between the Pacific Plate and the North American Plate, based on crustal deformation data. Postseismic crustal deformation was also observed by GEONET. Even though the area that coseismicaly subsided is undergoing partial uplift from postseismic deformation, such uplift is not rapid enough to make up for the coseismic subsidence within the next several years.The earthquake caused liquefaction in large parts of the Kanto Region, especially on the Tokyo Bay side and at the lower reaches of the Tone River. Liquefaction was concentrated in areas of land reclamation and former river channels, where it is easy to recognize using time-series geospatial information such as olden topographic maps and olden aerial photographs. To determine the amount of land subsidence (cm) due to liquefaction in Urayasu City, the GSI carried out a leveling survey and compared the differences between pre- and post-earthquake LIDAR survey data with the relative subsidence obtained by leveling.

Experimental study on the mechanism of non-synchronism of seismo-electromagnetic radiation precursors

In order to investigate the physical mechanism of non-synchronism of seismo-electromagnetic radiation precursors, we have made shear fracture and frictional sliding tests of rock samples by loading them in biaxial compression to model the activity of tectonic fault zones in seismogenic region. By installing antennae of different frequency responses and acoustic transducers around the fracture surface, the signals of electromagnetic radiation and acoustic emission in different directions and of different frequencies produced by rock samples during their shear fracturing and frictional sliding have been recorded by an automatic, high-speed and continuous observation system. Some implications given by the experimental results are as follows. The authors hold that electric signals (E) and magnetic signals (M) are of different genetic mechanisms: electric signals from inside the rock sample are produced by the piezoelectric effect of rock-forming crystals and net electric charge produced by the newly created surfaces due to rock fracture, whereas magnetic signals are produced by the high-speed motion of charged rock fragments and the ionization of ambient air excited by electrons emitted by rock in fracturing. Analysis shows that in some moderately strong earthquakes the electric and magnetic signals also showed the phenomenon of non-synchronism: the electric signal was earlier than the magnetic signal. If the same station observes simultaneously the electric field (underground) and magnetic field (air), the efficiency of earthquake prediction by seismo-electromagnetic radiation precursors would be raised effectively.

Current observation system using ship drift and its applications in Kumano-nada and Enshu-nada Seas

A continuous observation system of ship drift of ferry boats was developed using Loran C, ship direction, ship speed and wind velocity measurement. A formula to estimate the wind-driven lateral drift of the boat is proposed, and a measuring system of the surface current is described, including a discussions on its usefullness to monitor day-to-day variations of the circulation patterns in the coastal boundary regions of the Kuroshio.This system was applied to observe variations of the circulation in the Kumano-nada, and Enshu-nada Seas south of Japan. Some preliminary results were obtained by using this system as well as other methods. This work focuses on the behavior of warm eddies in the Kumano-nada Sea. The surface current patterns that include these phenomena obtained by the use of the ship drift show good correspondence with currents and thermal structures observed with GEK, CTD, moored current meters and satellite thermal images.