National Institute of Hospital Administration

Abstract. Cloud vertical structure plays a central role in regulating Earth’s radiation balance and hydrological cycle, yet it remains poorly represented in weather and climate models due to limited high-resolution observations. Using a newly established national network of 80 Ka-band cloud radars, we provide the first high-spatiotemporal-resolution characterization of cloud vertical structure across China for 2024 and quantify its thermodynamic, dynamical, and land-surface controls. An improved retrieval algorithm accounting for height-dependent radar sensitivity and clutter suppression is applied to derive cloud boundaries. The national annual mean cloud occurrence frequency is 56.7 %, dominated by single-layer clouds (34.7 %), followed by two-layer (14.7 %) and multi-layer clouds (7.1 %). Single-layer clouds prevail over arid northwestern China, whereas multi-layer clouds are more frequent in humid southeastern regions. Cloud base height exhibits strong seasonality, with higher values in summer and lower values in winter, and distinctly lower bases over the Tibetan Plateau. Diurnally, summer clouds show a pronounced afternoon peak between 3 and 9 km, while winter clouds are mainly confined below 3 km with a near-sunrise maximum. Thermodynamic conditions exert primary control on cloud vertical development. Higher low-level humidity favors deeper clouds and higher tops, whereas stronger lower-tropospheric stability suppresses vertical growth. Wind shear generally limits cloud depth, though moderate shear may enhance organization under unstable conditions. Land-surface characteristics further modulate cloud base height, with higher bases over barren land and lower bases over forests. These results provide national-scale observational benchmarks for improving cloud parameterizations in numerical models.

Cantilevered unstable rock masses constitute a prevalent geological hazard, with their stability intrinsically governed by the depth of trailing edge cracks. Traditional stability assessment methods, which largely rely on static calculations or displacement monitoring, often suffer from poor timeliness and insufficient early warning capabilities. To address these limitations, this study employs the Extended Finite Element Method (XFEM) to simulate the natural crack propagation trajectory and investigate the associated dynamic response characteristics under loading. The simulation results demonstrate that XFEM effectively captures the natural “vertical-to-oblique” fracture morphology, overcoming the limitations of pre-defined crack models. A critical correlation is established between crack evolution and natural frequency: the first-order natural frequency exhibits a staged decline, characterized by a precipitous drop of approximately 7 Hz during the late stage of fracture development (80–97% depth). Consequently, a “crack evolution–frequency response” model is proposed. This model confirms that natural frequency is a significantly more sensitive indicator of internal damage than displacement, providing a novel theoretical foundation and technical pathway for the early identification and dynamic evaluation of rock mass stability.

Anisometropic amblyopia is the most common cause of visual morbidity in childhood which is characterized by reduced spatial vision due to refractive error. This study was planned to determine the visual outcome after full refractive correction of anisometropic amblyopia among 5-15 years old children. The Cross sectional interventional study was conducted conducted in the Departments of Community Ophthalmology and Ophthalmology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from March 2017 to august 2019. Children (5-15 years) having myopic, hypermetropic & astigmatic refractive error between two eyes will be minimum 1.0 D difference after refraction and didn’t get any treatment for this problem yet were the study population. Total 52 untreated children were included in the study. 3 children did not attend the follow up visit. The mean age of the subjects of our study was 9.47 years, range of age was 5-15 years. 44 (89.8%) patients were bilateral & 5 (10.2%) were unilateral. After full correction of refractive error with spectacles alone improved anisometropic amblyopic eyes visual acuity an average of 2.3 lines in snellen’s chart. Visual acuity improved from baseline by 2 or more lines (95% CI) in 85% of the patients and by 3 or more lines in 49.3%. This improvement is statistically significant (P<0.0001). Additionally, amblyopia resolved in 7 of 49 (15%) patients with residual amblyopia who continued to be treated with spectacles even after completion of follow up plan. Improvement of visual acuity continued beyond the initial 12 weeks of spectacle wearing for 37 (75.5%) of the 49 patients completing the initial 12 week visit, after completing 24 weeks, it was 26 (53.1%). The mean VA of the right eyes at baseline was 0.45 Log MAR unit. In 2nd visit shows the mean of VA is 0.34 log MAR unit and in 3rd visit mean is 0.23 log MAR unit. Total improvement in right eye was 0.22 logMAR unit. The mean VA of the left eyes at baseline was 0.51 LogMAR unit. In 2nd visit shows the mean of VA is 0.37 logMAR unit and in 3rd visit VA mean is 0.30 logMAR unit. Total improvement in right eye was 0.21 logMAR unit. Average improvement in both eyes 0.215 logMAR unit. So, results shows that refractive correction is a powerful treatment modality for young children with anisometropic amblyopia. If we can detect them earlier then we should have given these children a better vision & prosperous life. J.Natl.Inst.Ophthalmol.2024;7(2): 20-27

<strong class="journal-contentHeaderColor">Abstract.</strong> Wildfires can significantly enhance surface sensible heat and modify the state of the near-surface atmosphere, becoming key factors in triggering turbulence and restructuring the boundary layer. This study uses high-resolution simulations with WRF-Fire, combined with hourly observational data from six meteorological stations (five national and one emergency stations) during the Jinyun Mountain wildfire in Chongqing, China, to systematically evaluate the performance of five planetary boundary layer (PBL) schemes (MYJ, MYNN2, MYNN3, BouLac, UW) in simulating temperature, wind speed, and turbulence intensity. Results show that all schemes can reproduce the diurnal trends of temperature and wind speed but exhibit significant differences in amplitude response and simulation errors. The MYNN3 scheme captures the spatiotemporal variations of turbulence intensity and wind speed at different heights more accurately, thereby better representing the 2-meter temperature and 10-meter wind speed response and reduces the model&rsquo;s cold bias in high-temperature simulations. The BouLac and MYNN2 schemes also show some response to thermal disturbances at certain sites but perform poorly under strong perturbations and exhibit large fluctuations. The MYJ and UW schemes show overall weaker turbulence and fail to capture local circulation variations effectively. Turbulent energy budget analysis of MYNN3 indicates a buoyancy-dominated turbulence generation mechanism, with vertical transport promoting upper-level disturbances. This reveals MYNN3&rsquo;s greater sensitivity to wildfire thermal perturbations and more complete feedback processes, providing a scientific basis for selecting PBL schemes in mountainous wildfire simulations.

This study presents a case study of the Ms5.5 Dezhou Earthquake to document the spatiotemporal characteristics of Outgoing Longwave Radiation (OLR) anomalies and their concurrent patterns with tidal force cycles. Based on NOAA satellite OLR data, synchronous monitoring and comparative analysis were conducted with tidal force variation cycles. The results show that pronounced OLR anomalies were concentrated exclusively in the co-seismic tidal cycle (Cycle C: 23 July–5 August 2023), while no significant anomalies were detected in pre-seismic Cycles A/B and post-seismic Cycle D. Temporally, the OLR anomalies in Cycle C exhibited a distinct six-stage evolutionary pattern: initial warming (31 July) → rapid intensification (1–3 August) → peak (4 August) → abrupt decline (5 August) → post-seismic pulse (6 August) → exponential decay (7–9 August). Spatially, the anomalies were closely distributed along the Liaocheng–Lankao Fault, showing a NE-trending (N35°E) distribution that matches the structural characteristics of the fault zone. Additionally, the spatial extent of OLR anomalies (within 400 km of the epicenter) is consistent with the effective detection range of co-seismic electromagnetic signals reported in existing studies. This study provides a typical observational case of OLR anomaly characteristics associated with medium-magnitude earthquakes, offering a reference for understanding the spatiotemporal evolution of seismic thermal anomalies.

Abstract This study investigates the four‐peak electron density structure in the Equatorial Ionization Anomaly (EIA) during the intense geomagnetic storms of 10–20 May 2024, utilizing dayside data at ∼500 km from the China Seismo‐Electromagnetic Satellite (CSES‐01). Observations revealed distinct four peaks in latitudinal profiles of electron density, symmetrically distributed across both hemispheres. Particularly, the poleward crests can expand beyond ±30° quasi‐dipole latitude during the 10 May superstorm. To reveal the potential driver of such unique EIA structure, statistical analysis is conducted on 35 CSES‐01 orbits which identified the four‐peak phenomenon. The enhanced equatorial electrojet activity, inferred from the scalar magnetic field residuals, indicates that the four‐peak morphology is likely related to the prompt penetration electric field (PPEF). Superposed epoch analysis also highlighted that intensification of the mean SuperMAG |SML| index preceded the onset of four‐peak structures by ∼20 min, whereas the mean eastward equatorial electric field, derived from an empirical model of the interplanetary electric field driven penetration, exhibits no statistically significant enhancement, implying that substorm‐associated PPEF may be the primary driver of this type of EIA structure. This study advances understanding of EIA variability under extreme space weather conditions and the findings underscore the critical role of magnetosphere‐ionosphere coupling via substorm‐driven electric fields in reshaping storm‐time ionospheric plasma distribution.