Harmful Algal Bloom Monitoring System

We've updated the look of our Lake Erie HAB Bulletins

The imagery for the Lake Erie Bulletin is changing to a new color scale. This scale is more consistent in brightness, and follows from advances in the understanding of how people interpret color. To help with interpretation of the bulletins, we have taken several bulletins from 2017 (strong bloom) and 2018 (milder bloom) and applied the new color scale. These pairs of bulletins include a range of conditions to help people see how any bloom scene in 2019 might look compared to these years.

The previous color scheme was based on the “rainbow” colormap that has been widely used in many programs. The new color scheme is based on the “viridis” colormap developed by University of California at Berkeley. Viridis has a uniform change in both hue and brightness. The rainbow doesn’t, with some colors popping out. That also makes it more difficult for people with color deficiency. We added red at the high end of Viridis, but following the method of changing brightness and hue consistently.

View side-by-side comparison of the old and new color scales.

See the examples below and view other examples of previous bulletins using the new color.

Old Format


New Look