Leading scientists in the United States warn that the long-term effects of the El Niño phenomenon could cause the Amazon to experience more intense forest fires this year.
The El Niño of 2015 and the early part of 2016 have impacted rainfall patterns in the different parts of the world.
One of those significantly affected by the extreme weather condition is the Amazon, which saw a considerable decrease in the amount of rainfall during its wet season. This left the region to experience its driest point since 2002 by the time it entered its dry season this year, according to satellite data from NASA.
Doug Morton, an expert on Earth science from NASA, said that this year's El Niño phenomenon has also made the Amazon more susceptible to wildfires than in 2005 and 2010, when the region suffered from widespread forest fires brought on by drought.
Morton explained that the southern part of the Amazon is now at a high risk for wildfires due to the severe drought conditions the area has been undergoing since the beginning of the dry season.
Forecasting Wildfires In The Amazon
To find out the risks of forest fires in the Amazon, scientists made use of a system developed by NASA and the University of California, Irvine (UCI). This technology examines the relationship between climate and active fire detection data from NASA satellites in order to determine the severity of the region's fire season.
The forecast model centers on the connection between fire activity and sea surface temperatures. The Amazon becomes more susceptible to wildfires whenever higher sea surface temperatures in the Atlantic and Pacific oceans alter weather patterns in the region, causing it to experience significantly less rainfall.
The team also studied terrestrial water storage data from the Gravity Recovery and Climate Experiment (GRACE) mission in order to identify changes in the groundwater in the Amazon during its dry season. These measurements were used as a substitute for the relative dryness of forests and soils.
NASA and UCI researchers have coordinated with scientists and officials in South America to raise their awareness on wildfire forecasts over the years.
Liana Anderson, a scientist from Brazil's National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN), said the wildfire forecasts are crucial since they allow them to know which particular areas are more likely to suffer forest fires. This gives them an opportunity to coordinate their plans in support of local efforts.
Real-Time Tracking Of The Amazon's Fire Season
According to recent estimates, El Niño-related conditions in the Amazon have become much drier this year than during the drought years of 2005 and 2010. NASA and UCI scientists have created a web tool to help them monitor the progress of the region's fire season almost in real time.
Fire emission readings from each one of the forecast regions are updated every day using active fire detection data gathered through the Terra satellite's Moderate resolution Imaging Spectroradiometer (MODIS) instrument, as well as fire emissions data from previous years recorded in the Global Fire Emissions Database (GFED).
Using these data, the researchers discovered that the Amazon has experienced more wildfires in recent times than in any other point in history, which is in accordance with the forecast on the region's fire severity.
Jim Randerson, a scientist from UCI and one of the developers of the forecast model, said trees become more susceptible to fires and evaporate lower amounts of water into Earth's atmosphere when they don't have enough moisture to draw upon at the start of the dry season.
During such scenarios, Randerson said millions of trees are exposed to higher levels of stress, lowering the available humidity across their region. This in turn causes forest fires to become larger than what they would typically be under normal conditions.