strong storm over Scandinavia strong storm over the British Isles and Norway cyclone Lothar cyclone Martin -35 0 35 sea level pressure anomaly [hPa] linearized space linearized space Figure 1. A temporal merge tree map (top) is a static visualization of a time-dependent scalar field (bottom). Our method uses augmented merge trees to map the data samples of each time step to a vertical slice. An optimization scheme is employed to achieve a temporally coherent mapping. The shown Storms data set represents storm activity over Europe in December 1999 and contains 744 time steps, arranged from left to right. Cyclones can easily be identified as dark blue lines and compared with each other wrt. their strength, lifetime, and footprint, while still being shown in the context of the entire data. Temporal merge tree maps can serve as data analysis tools in their own right, or be used to augment animations and other views. With some parallel processing, the above image can be computed in less than 15 seconds.