File:Fires in Argentina and Paraguay (MODIS 2022-02-02).jpg

English: Heavy smoke from multiple fires rose across parts of South America in late January 2022. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the scene on January 31.

Most of the smoke appears to rise from fires in northeastern Argentina (located in the southwest portion of the image) and blows northward to blanket Paraguay. Smoke also rises in Uruguay (southeast). The landscape overall appears quite dry, washed more in tan and faded green rather than the lush greens that are typical of the region during normal times.

Much of Central South America, including Paraguay, Uruguay, and much of Argentina, has been experiencing long-term drought. According to the Global Disaster Alert and Coordination System (GDACS), the drought began in December 2019 and that “drought indicators suggest anomalies typical of extreme to severe events”. As the harvest date nears for soybean and corn, the lack of rain and soaring temperatures—media reports of highs around 45˚C (113˚F) in parts of Argentina recently—has severely damaged many crops, slashing estimates of harvest. Along with reduced harvest comes substantial loss of income for farmers across the region. In early January, the government of Paraguay announced new programs to aid the agricultural sector amid crop losses and drought.

The true-color MODIS image above uses visible light (data from bands 1,4,3) to show what the scene would look like if viewed by the human eye from above the landscape. The MODIS instrument also is equipped with thermal detectors, which provide a powerful way to detect areas that are hot compared to background. This feature of the instrument is often used to easily and detect actively burning fires, either in small areas or across large swaths of the Earth—both during the day and at night. When MODIS thermal detectors are used to create an image, the hot areas (hot spots) are marked in red.

While the true-color, daytime view of the fires burning in Central South America is interesting, additional information can be gained by also taking a night-time look at the hot spots across the region. Thanks to the NASA Worldview App, it’s easy to create such a view from the data gathered by MODIS. To see the nighttime view, click here . While it’s not possible to determine the cause of fires from satellite imagery, the number of fires, location, and time of year suggests they are agricultural in origin, and have been deliberately set to manage cropland or pasture.