Hovmöller DiagramsMay 10, 2015
A Hovmöller diagram is a meteorological visualization technique for time-varying geospatial data. In 2D, the diagram looks like a map where one of the dimensions (latitude or longitude) has been replaced by a timeline. The color of the plot indicates the value of some quantity (temperature, for example). The limitation of such a representation is that you can only show a "slice" of the geography in question, so coordinates must be chosen carefully or many plots must be compared simultaneously. Hovmüller plots also look a lot like maps, so it can be confusing to overcome built-in intuition about how to read a map and use the visualization effectively.
Computer graphics can overcome some of the limits of the 2D visualization. One of the many cool visualizations to come out of the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT) project is a version of the Hovmöller diagram formed by crossing three 2D plots (lat-lon, lon-time, lat-time) in an interactive 3D space where time is the vertical axis. This format is a lot easier to interpret because the horizontal plane is just a regular geographic map colorized to show temperature. The true Hovmüller plots are on the vertical planes.