This image, from the NASA SeaWiFS project, shows the striking green colors produced by phytoplankton.
You probably already know that a hurricane has an eye, but did you know that hurricanes might actually display a preference for certain colors? New research from the U.S. Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey suggests that hurricanes may be more likely to travel over green areas of the ocean than over more clear, blue areas. The ongoing study is attempting to improve hurricane forecasting models by looking at variables like ocean color which are not usually considered in tracking programs.
The study looked specifically at storms in the northern Pacific Ocean, where the predominant surface water color is green due to blooms of tiny plants called phytoplankton. These plants absorb sunlight, which increases the water temperature in that area. Increased surface temperature means increased “fuel” for hurricanes, which gain strength over warm water and lose strength over cooler water or land. The researchers used a computer program to model what would happen to hurricane paths if the phytoplankton were reduced in number, thus changing the water color. As the water became clearer, the number of hurricanes traveling over that region of water was reduced by two-thirds.
These results suggest that if phytoplankton populations decrease, fewer hurricanes may travel north to highly populated areas like Japan or the East Coast of the United States. Several studies have suggested that in fact this may already be happening, as global warming has made some areas of the ocean less hospitable to phytoplankton. However, other studies have suggested that global warming is actually increasing phytoplankton populations, so more research is needed in this area. And of course, while it would be great to not have to worry about hurricanes outside of the tropics, removing phytoplankton could have a severely negative effect on marine environments that rely on the plants for energy.
The researchers are now planning to move their study into the real world by looking at actual hurricane paths and satellite imagery of real-time ocean colors to see if their preliminary results match up with real storm paths. In the meantime, if you’d like to learn more about hurricanes and other types of storms, visit Morehead Planetarium and Science Center to see Science 360: Predicting Severe Weather when it comes back on our Fall schedule September 4.
Casey Rawson is the Science Content Developer for Science 360.