晕渲图技术在气象模式数据可视化上的应用  

Application of Relief Shading Method in Meteorological Model Data Visualization

作　　者：沃伟峰 王岩 赵昶昱 徐蓉 徐迪峰 WO Weifeng;WANG Yan;ZHAO Changyu;XU Rong;XU Difeng(Ningbo Meteorological Bureau,Zhejiang,Ningbo 315012;Ningbo Key Laboratory of Smart Meteorology,Ningbo 315012;Academician Workstation of Ningbo Meteorological Observatory,Zhejiang,Ningbo 315012;Pudong District Meteorological Bureau,Shanghai 200135)

机构地区：[1]浙江省宁波市气象局,宁波315012 [2]宁波市智慧气象重点实验室,宁波315012 [3]浙江省宁波市气象台院士工作站,宁波315012 [4]上海市浦东新区气象局,上海200135

出　　处：《气象科技》2024年第3期318-329,共12页Meteorological Science and Technology

基　　金：宁波市重点研发计划(2023Z139);宁波市公益性科技计划项目(2022S181);浙江省气象科技计划项目(2022ZD26)共同资助。

摘　　要：晕渲法根据山体阴影值的原理,利用光照角度和方向、坡度和坡向的关系来计算光通量的明暗值,利用色调的明暗来展现气象模式数据的立体感。晕渲图的着色方法是将每个格点上的明暗值作为HSV色彩模式中的明度,结合饱和度和色度获得HSV色彩值,再通过HSV色彩模式和RGB色彩模型之间的转换,使用RGB色彩模型进行着色,实现气象模式数据彩色晕渲图的绘制。本文在气象模式数据的可视化工作中,利用晕渲图技术,实现对物理概念上与地形类似的气压、位势高度等数据的三维绘制。相比于传统的等值线填色方法,晕渲图技术能够直观表现大气形势场的立体分布,以凹凸效果表现高低值天气系统,通过坡面的陡度体现天气系统的梯度变化;能够展现数据的像素级细节,识别梯度较小的涡流扰动,显示等效地形影响,帮助气象工作者更好地解释数据,为气象模式中数据处理的改进提供参考。By introducing the relief shading method,which is often used in making the topographic maps,into the visualisation of numerical weather forecast data,this article presents the achievement in three-dimensional drawing of meteorological variables,such as air pressure and geopotential height.Based on the principle and implementation of hill shading,which uses the relationship between the illumination angle,the direction,the slope,and the orientation of the terrain to calculate the brightness value of luminous flux,the relief shading method makes use of the brightness value to display the three-dimensional sense of meteorological model data.At the same height,the steeper the terrain,the darker(brighter)the shaded(sunny)side;under the same slope,the higher the terrain,the darker(brighter)the shaded(sunny)side,which is consistent with the real-life visual effect.The colouring method of the shaded relief map is to use the brightness value(V)in the HSV colour space which is calculated on each grid point,combined with hue(H)and saturation(S)to obtain a complete HSV colour scheme.Through the conversion from the HSV colour space to the RGB colour space,the latter colour space is used for drawing a coloured shaded relief map for meteorological model data.In the shaded relief map,the high-pressure centre in the weather system is often shown as a raised peak,and the low pressure is shown as a depressed valley;a large pressure gradient can be seen as a steep slope,while a small pressure gradient can be seen as a gentle slope.Compared with the traditional isoline and colour filling analysis,it is found that the shaded relief map can help to identify high-low weather systems by concave-convex shapes and reflects the gradient changes of weather systems through the steepness of slope,thus intuitively representing the three-dimensional distribution of atmospheric circulation.In addition,the shaded relief map has the ability to visualise model data in pixel level details,identify early eddy current disturbances in small gradients,and

关 键 词：晕渲图 气象模式数据 三维可视化 HSV模型 

分 类 号：P415.2[天文地球—大气科学及气象学]