Ten years ago today, New Orleans was hot and humid, as it is every summer. But the Big Easy was 10 days out from one of the worst disasters in U.S. history. Hurricane Katrina had still not even formed in the Atlantic – and the coming deluge seemed unimaginable.

A decade later, scientists are still trying to better understand long-term weather patterns and how they link together. Climate scientists from UC Irvine and NASA found a strong north-south link between tropical hurricane development and fires in the Amazon rainforest, as they report in the journal Geophysical Research Letters.

“Hurricane Katrina is indeed part of this story,” said James Randerson, a UC – Irvine professor and senior author of the paper. “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 these events is perfectly consistent with our research findings.”

While the east-west effect of El Nino on the Amazon and elsewhere has been well researched and understood, the north-south effect has not been as well catalogued. But it is straightforward, said Yang Chen, the lead author of the new study: warmer water in the North Atlantic pulls moisture away from the Amazon. This both adds to the volatility for hurricanes to develop, and drier harsher fires in South America – like was the case in the late summer of 2005.

Linking the two phenomena might help with long-range models of prediction and understand larger climate patterns, the authors added.

“The synchronization of forest damages from fires in South America and tropical storms in North America highlights how important it is to consider the Earth as a system,” said Douglas Morton, of NASA’s Goddard Space Flight Center, and one of the authors.

Climate experts from Colorado State University had predicted one of the last-active hurricane seasons in decades back in April. However, a tropical storm currently swirling in the Atlantic could become the first hurricane of the season in the coming days, according to meteorologists.
http://www.laboratoryequipment.com/news/2015/08/nasa-uc-irvine-researchers-look-amazon-fires-link-hurricanes-10-years-after-katrina