The model grid Hybrid vertical coordinate
{"Image DocumentName": "The model grid Hybrid vertical coordinate", "Image ImageDescription": "Combination of terrain following and atmospherics pressure. 19 vertical levels (lowest at 50m, highest at 5Pa) Regular lat-lon grid in the horizontal. \u2018Arakawa B\u2019 grid layout. P = pressure, temperature and moisture related variables. W = wind related variables. W. P. Now back to the model grid, which is very important as this is the grid on which all of your model results will be on. The vertical component of this grid uses a so called hybrid coordinate system. It is hybrid in the sense that each vertical level is specified as a linear combination of a terrain following height-above-the-surface coordinate and an atmospheric pressure coordinate. The number of levels is fixed at 19: the lowest four are purely terrain following, the uppermost three near the top of the atmosphere are purely pressure levels and levels 5 to 16 are a fixed linear combination of the two types of coordinate. Within each vertical level is a horizontal grid which uses a latitude/longitude spherical polar coordinate system with regular grid spacings in both latitudinal and longitudinal directions. And furthermore, within this horizontal grid the wind variables are simulated on a grid that is offset by half a grid box in each direction from all of the other variables. This particular layout of two staggered horizontal grids is known as an \u2018Arakawa B grid\u2019 and is used for its numerical stability properties. \u00a9 Crown copyright Met Office.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}