Snow sublimation is an important hydrological process and one of the main causes of the temporal and spatial variation of snow distribution. Compared with surface sublimation, drifting snow sublimation is more effective due to the greater surface exposure area of snow particles in the air. Previous studies of drifting snow sublimation have focused on suspended snow, and few have considered saltating snow, which is the main form of drifting snow. In this study, a numerical model is established to simulate the process of drifting snow sublimation in the saltation layer. The simulated results show 1) the average sublimation rate of drifting snow particles increases linearly with the friction velocity; 2) the sublimation rate gradient with the friction velocity increases with increases in the environmental temperature and the undersaturation of air; 3) when the friction velocity is less than 0.525 m/s, the snowdrift sublimation of saltating particles is greater than that of suspended particles; and 4) the snowdrift sublimation in the saltation layer is less than that of the suspended particles only when the friction velocity is greater than 0.625 m/s. Therefore, the drifting snow sublimation in the saltation layer constitutes a significant portion of the total snow sublimation.

Abstract. Drifting snow sublimation (DSS) is an important physical process related to moisture and heat transfer that happens in the atmospheric boundary layer, which is of glaciological and hydrological importance. It is also essential in order to understand the mass balance of the Antarctic ice sheets and the global climate system. Previous studies mainly focused on the DSS of suspended snow and ignored that in the saltation layer. Here, a drifting snow model combined with balance equations for heat and moisture is established to simulate the physical DSS process in the saltation layer. The simulated results show that DSS can strongly increase humidity and cooling effects, which in turn can significantly reduce DSS in the saltation layer. However, effective moisture transport can dramatically weaken the feedback effects. Due to moisture advection, DSS rate in the saltation layer can be several orders of magnitude greater than that of the suspended particles. Thus, DSS in the saltation layer has an important influence on the distribution and mass–energy balance of snow cover.

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With the rapid development of medical technology, 3D printing technology with realistic representation can perfectly display static human anatomy, while 3D visualisation technology based on Web Graphics Library (WebGL) can promote the rigid replication characteristics of traditional teaching models and express the dynamic spatial relationship between different anatomical structures. Medical students traditionally have less cognition of ankle ligament sprains. In this study, computed tomography (CT) and magnetic resonance imaging (MRI) data of the ankle joints of volunteers were used to print models of the ankle bone, tendon, and ligament using 3D printing technology, and a real-time interactive 3D digital model of the functional ankle joint was designed using 3D visualisation based on WebGL and 2D image real-time rendering technology for interactive teaching. The utility of the 3D printing model combined with the WebGL-based 3D digital teaching model was evaluated in comparison with traditional teaching methods in 24 medical students. The results showed that the total score of students in the experimental group (mean ± SD, 79.48 ± 12.93) was significantly better than that of the control group (61.00 ± 14.94) with P < 0.05. The practical test scores of the experimental group (18.00 ± 2.70) were significantly higher than those of the control group (13.67 ± 4.96) with P < 0.05. In the satisfaction survey, the feedback questionnaire showed that the interactive teaching model of 3D printing technology combined with WebGL-based 3D visualisation technology was recognised by students in terms of quality and overall satisfaction. In addition, female students who used 3D printing combined with WebGL-based 3D visualisation technology as learning aids had a greater difference in practical test scores from the control group than male students. This study has demonstrated that the interactive teaching mode of 3D printing combined with WebGL-based 3D visualisation technology is beneficial to the teaching of medical imaging, enriching the learning experience of students, and increasing the interaction between teachers and students.