Tropical Storm Nestor dropped much-needed rain on Hall County and moved on. In its wake we enjoyed a sunny Sunday with balmy 78-degree highs. This illustrates the job that tropical storms and hurricanes have in nature’s system. Although they cause a lot of damage to the human habitat, especially along coast lines, they aren’t designed to be a nuisance. The tropics (on our land mass, roughly the area between Cuba and Peru) receive more sunlight than other regions. This produces an energy imbalance that must be resolved. Heat from warm ocean water causes evaporation. Water vapor rises into the atmosphere, loaded with energy. A few more things occur up in the air, and a tropical storm is born. If it gets powerful enough, it may achieve hurricane status with winds speeds 75 mph or higher.
What makes these tropical systems different from the storms we see here in winter is that they aren’t of the cold-core type. Winter storms in Georgia come from Canada, driven by big masses of dry, cold air that comes to the South in order to fight with our warmer air. Their tropical cousins, though, consist entirely of warm air, loaded with moisture. They have no cold fronts or warm fronts, unlike the winter storms. Once they crash ashore, they unload their cargo of wind and rain on the coast. This is beneficial for undeveloped coast lines. On the U.S. West Coast, rock loosened by weathering and earth tremors gets hammered by the waves until it breaks and falls down to a more stable position. On the East Coast, the waves wash across the barrier islands, creating wide sandy beaches.
In the process, nature doesn’t consider the structures that people have put on the coast. For an example of the ocean swallowing real estate, look at Pacifica, California on Google Earth. Houses teetering on the edge of cliffs weren’t built in that position in the first place. On Georgia’s coast, along with the Carolinas, Florida and Virginia, any barrier island town has a history of destruction by the waves. On the Gulf Coast, Google Earth still shows the damage done to Mexico Beach, Florida when hurricane Michael lashed the area in October 2018. Although costly for towns that are in the way, all tropical storm systems are a necessity for nature to keep its energy budget balanced.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.