Pine wilt disease (PWD), caused by the pine wood nematode (Bursaphelenchus xylophilus), is a major threat to Pinus thunbergii forests in South Korea. Although climatic conditions are known to affect the spread of PWD, the specific influences of temperature and geography on nematode density and tree mortality remain unclear. This study assessed monthly PWN density and black pine mortality across three regions—two coastal (Geoje and Sacheon) and one inland (Jinju)—from 2021 to 2023. Nematode density and tree mortality consistently peaked in autumn across all regions. A strong positive correlation was observed between nematode density and tree mortality (r = 0.7468, p < 0.01), while temperature showed no significant correlation with either variable. These results indicate that PWD severity is more closely tied to nematode activity than to temperature alone, and that regional and seasonal variability must be considered in disease assessment. The findings highlight the need for region-specific monitoring and management strategies that prioritize high-risk periods, particularly autumn, when nematode activity and disease expression are most pronounced. This research provides essential data to support adaptive PWD control programs under changing climatic conditions.

We investigated three fan-shaped jets observed above sunspot light bridges or nearby sunspot regions. The study aimed to explore the dynamics and physical properties of jets’ features that appear as blob-like structures at the tips of the jets, which we call ‘dark blobs’. A transparent region is observed beneath the dark blobs, creating a visible gap between the dark blobs and the trailing body of the jets. These phenomena were studied in chromospheric and transition region imaging and spectral high-resolution co-observations from the Visible Imaging Spectrometer of the Goode Solar Telescope at the Big Bear Solar Observatory and the Interface Region Imaging Spectrograph (IRIS), together with data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We analyzed the jets’ morphology and fine structure. We obtained the spatial scale and the dynamics of the dark blobs that are seen mostly in the wings of the Hα line and have a cross-section of about 0.2′′–0.3′′. The dark blobs and the transparent regions are seen bright (in emission) in the IRIS slit-jaw 1330 Å, 1400 Å, and AIA 304 Å images. The IRIS Si iv 1394 Å spectrum of the brightenings showed blue-shifted emission of about 16 km s−1 with non-thermal velocities of up to 40 km s−1. We also estimated the electron density of the blue-shifted brightenings to be 1012.1±0.2 cm−3. Our findings likely suggest that we detect the observational signatures of shock waves that generate and/or contribute to the evolution of fan-shaped jets.

The Challan instrument is a solar full-disk imaging spectroscopic telescope planned to be installed at three sites with a 120-degree longitudinal difference, enabling continuous 24-hour observations of the Sun. It will take data every 2.5 min with a spatial resolution of 2–3′′ and a spectral resolving power (R) of >43,000 in Hα and Ca ii 8542 Å bands simultaneously. Challan is composed of two modules, each dedicated to a specific waveband. This modular design is beneficial in minimizing the scattered light and simplifying the structure and engineering. The primary scientific goal of Challan is to investigate solar flares and filament eruptions. It is also expected to detect small-scale events in the solar chromosphere. In 2025, Challan will be installed at the Big Bear Solar Observatory for test observational runs, followed by scientific runs in 2026.

남방큰무당벌레(신칭)를 한국 미기록종으로 보고한다. 본 종은 국내 Harmornia속의 3종과는 둥글고 볼록한 체형, 앞가슴등판의 갈라진 점 모양, 각 딱지날개에 7개의 검은점이 1-3-2-1 배열로 나타나는 특징으로 쉽게 구별할 수 있다. 본 연구에서는 Harmonia속의 종 검색표, 진단형질과 DNA바코드 정보를 제공하고자 한다.