최근 지구온난화로 인한 기후변화는 육상 및 해양 생태계에 다양한 영향을 미치고 있다. 농업생태계 역시 이들 생태계에 의존하고 있는 생물 및 인간에게 생물학적, 경제학적, 사회학적으로 다양한 영향을 주고 있다. 기후변화를 쉽게 감지할 수 있는 지표종은 기후변화에 비교적 민감하게 반응을 나타내기 때문에 농업생태계와 같은 경제 사회적 영향을 많이 받는 곳에서 다양하게 활용될 수 있다. 2017년 농업과학원에서는 농업생태계에서 기후변화에 따른 영향을 잘 나타낼 수 있는 식물과 무척처동물 30종을 지표종으로 선정하였다. 30종 중 나비목에 속하는 종으로는 배추흰나비(Pieris rapae), 남방노랑나비(Eurema mandarina), 노랑나비(Colias erate), 호랑나비(Papilio xuthus) 4종이다. 이 연구는 나비 지표종 중 농업생태계에서 가장 풍부하고 확인이 쉬운 배추흰나비를 대상으로 전남, 충북, 경기, 강원지역에서 4월부터 월 1-2회 모니터링을 실시하여 생물계절의 차이를 알아보았다. 조사는 각 지역에서 논과 밭, 산림 등을 포함하는 경로를 선정하여 30분간 이동하면서 좌우 5m내외 출현하는 나비를 조사하는 선 조사법을 실시하였다. 4월 이후부터 조사한 결과 전남에서는 4월초인 14째 주에 이미 많은 수가 관찰된 반면 충북, 경기 등지에선 15째 주 이후 관찰되기 시작하였다. 강원도에서는 6월 중순인 24째부터 관찰되어 위도별 출현 양상의 차이를 나타내었다. 9월말까지 관찰된 생활사 수는 전남에서는 5회, 경기도에서는 4-5회, 충북에서는 4회, 강원에서는 2회로 지역별 차이를 나타내었다. 이러한 결과는 농업생태계에서 흔히 볼 수 있는 배추흰나비가 위도별로 출현시기와 출현횟수를 달리하면서 나타나는 것을 통해 기후변화를 나타낼 수 있는 지표종으로 적절하다고 여겨지며 앞으로도 전국적으로 지속적인 모니터링을 통해 정밀한 출현양상과 미래 분포 변화 모델링 작업에 효과적으로 이용될 수 있는 기초자료를 제공할 수 있을 것으로 여겨진다.

Halo coronal mass ejections (CMEs) originating from solar activities give rise to geomagnetic storms when they reach the Earth. Variations in the geomagnetic field during a geomagnetic storm can damage satellites, communication systems, electrical power grids, and power systems, and induce currents. Therefore, automated techniques for detecting and analyzing halo CMEs have been eliciting increasing attention for the monitoring and prediction of the space weather environment. In this study, we developed an algorithm to sense and detect halo CMEs using large angle and spectrometric coronagraph (LASCO) C3 coronagraph images from the solar and heliospheric observatory (SOHO) satellite. In addition, we developed an image processing technique to derive the morphological and dynamical characteristics of halo CMEs, namely, the source location, width, actual CME speed, and arrival time at a 21.5 solar radius. The proposed halo CME automatic analysis model was validated using a model of the past three halo CME events. As a result, a solar event that occurred at 03:38 UT on Mar. 23, 2014 was predicted to arrive at Earth at 23:00 UT on Mar. 25, whereas the actual arrival time was at 04:30 UT on Mar. 26, which is a difference of 5 hr and 30 min. In addition, a solar event that occurred at 12:55 UT on Apr. 18, 2014 was estimated to arrive at Earth at 16:00 UT on Apr. 20, which is 4 hr ahead of the actual arrival time of 20:00 UT on the same day. However, the estimation error was reduced significantly compared to the ENLIL model. As a further study, the model will be applied to many more events for validation and testing, and after such tests are completed, on-line service will be provided at the Korean Space Weather Center to detect halo CMEs and derive the model parameters.

Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.

Interplanetary scintillation-driven (IPS-driven) ENLIL model was jointly developed by University of California, San Diego (UCSD) and National Aeronaucics and Space Administration/Goddard Space Flight Center (NASA/GSFC). The model has been in operation by Korean Space Weather Cetner (KSWC) since 2014. IPS-driven ENLIL model has a variety of ambient solar wind parameters and the results of the model depend on the combination of these parameters. We have conducted researches to determine the best combination of parameters to improve the performance of the IPS-driven ENLIL model. The model results with input of 1,440 combinations of parameters are compared with the Advanced Composition Explorer (ACE) observation data. In this way, the top 10 parameter sets showing best performance were determined. Finally, the characteristics of the parameter sets were analyzed and application of the results to IPS-driven ENLIL model was discussed.

Coronal Mass Ejections (CME), which originate from active regions of the Sun’s surface, e.g., sunspots, result in geomagnetic storms on Earth. The variation of the Earth’s geomagnetic field during such storms induces surface currents that could cause breakdowns in electricity power grids. Hence, it is essential to both monitor Geomagnetically Induced Currents (GICs) in real time and analyze previous GIC data. In 2012, in order to monitor the variation of GICs, the Korean Space Weather Center (KSWC) installed an induced current measurement system at SINGAPYEONG Substation, which is equipped with 765 kV extra-high-voltage transformers. Furthermore, in 2014, two induced current measurement systems were installed on the 345 kV high-voltage transformers at the MIGEUM and SINPOCHEON substations. This paper reports the installation process of the induced current measurement systems at these three substations. Furthermore, it presents the results of both an analysis performed using GIC data measured at the SINGAPYEONG Substation during periods of geomagnetic storms from July 2013 through April 2015 and the comparison between the obtained GIC data and magnetic field variation (dH/dt) data measured at the Icheon geomagnetic observatory.