Natural disasters are one of people's greatest fears. Man does contribute to the changing environment that eventually causes calamities, but when nature gets upset and strikes from up in the atmospheres, from the ground or from below the deepest waters, there's nothing a man can do.
Wildfires and hurricanes, for example, take place only during specific times of the year, but when they do, everything is destroyed, from vegetation to animal life to urban structures. Imagine what it would be like if wildfires and hurricanes teamed up.
In a new discovery, researchers found that destructive wildfires may affect the formation of equally devastating hurricanes.
The University of California, Irvine and NASA reported having uncovered a strong link between high risks of wildfire in the Amazon basin and hurricanes that consume the shorelines of the North Atlantic. Findings of this new discovery will appear in the online journal Geophysical Research Letters near the tenth anniversary of Hurricane Katrina which took landfall in New Orleans and at the Gulf Coast August 2005.
According to Yang Chen from UCI's Department of Earth System Science, and the study's lead author, apart from El Niño's east-west influence on the Amazon, the tropical North Atlantic also sets a north-south influence on fire. When there is a high number of hurricanes and high risks of wildfire, waters in the North Atlantic become warm, leading hurricanes to develop and gather strength and speed that will take them to the shores of North America. Chen added that they also bring with them a "large belt of tropical rainfall" called the Intertropical Convergence Zone, bringing it away from the southern Amazon and into the north.
Ground water therefore does not become fully replenished at the end of the rainy season. When there isn't plenty of water stored in the soils during the next dry spell, plants cannot evaporate and transpire enough water into the atmosphere.
It becomes a cycle as the atmosphere becomes drier and drier, leading to conditions that, after three to six months, may ignite wildfires that rapidly spread out.
"Hurricane Katrina is, indeed, part of this story," said James Randerson, also from UCI's Department of Earth System Science. "The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once in a century dry spell in the Amazon. The timing of the events is perfectly consistent with our findings."
