Researchers link warming ocean to Amazon fires
Scientists from University of California, Irvine have created a computer model they say can successfully predict the location and severity of fires in the Amazon rain forest, and the rest of South America, months in advance. The model relies on small variations in ocean temperatures, combined with estimates of human impacts in the region, to predict how many fires a region might experience from one year to the next.
This very nice NASA video explains the story.
The scientists analyzed nearly a decade of satellite data in the process of creating their ocean-fire model.
Previous research in the Amazon has shown that human settlement patterns are the primary factor that drives the distribution of fires in the Amazon. The new research demonstrates that environmental factors – specifically small variations in ocean temperatures – amplify those human impacts.
Yang Chen, the University of California, Irvine, scientist who led the research. Chen and his colleagues found temperature changes of as little as .25°C (.45°F) in the North Atlantic and 1°C (1.8 °F) in the Central Pacific can be used to forecast the severity of the fire season across much of the Amazon. He said:
Higher than normal sea surface temperatures in the Atlantic and the Pacific proved to be red flags that a severe fire season was on its way in four to six months.
The researchers believe that unusually warm sea surface temperatures cause regional precipitation patterns to shift north in the southern Amazon during the wet season. James Randerson, a scientist at University of California, Irvine who co-authored the study, said:
The result is that soils don’t get fully saturated. Months later, humidity and rainfall levels decline, and the vegetation becomes drier and more flammable.
To establish the connection between fire activity and sea surface temperatures the researchers analyzed nine years of fire activity data collected by Moderate Resolution Imaging Spectroradiometer instruments (MODIS) on NASA’s Terra and Aqua satellites and compared the number of fires to records of sea surface temperatures maintained by the National Oceanic and Atmospheric Administration (NOAA). Years with anomalously cool ocean temperatures had fewer fires, while years that experienced unusually warm ocean temperatures experienced more fires. The team also looked for and found changes in precipitations patterns as measured by the Tropical Rainfall Measuring Mission (TRMM), a satellite managed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA).
Bottom line: Researchers at University of California, Irvine have used computer modeling to establish a link between rising ocean temperatures and increased numbers and severity of fires in the Amazon rainforest and throughout South America.