image: NASA's Suomi NPP satellite captured this natural-color image using the VIIRS (Visible Infrared Imaging Radiometer Suite) instrument on May 22, 2017 of the Cape York Peninsula in Queensland, Australia. The actively burning areas, detected by Suomi's thermal bands, are outlined in red. These fires, however, are not bushfires, they are prescribed fires. Prescribed fires are fires that are deliberately set by fire officials for a whole host of reasons. There are ecosystems that actually require fires for further growth. After many years of fire exclusion, an ecosystem that needs periodic fire becomes unhealthy. Trees become stressed by overcrowding; fire-dependent species disappear; and flammable fuels build up and become hazardous. The right fire at the right place at the right time can: Reduce hazardous fuels, protecting human communities from extreme fires; Minimize the spread of pest insects and disease; Remove unwanted species that threaten species native to an ecosystem; Provide forage for game; Improve habitat for threatened and endangered species; Recycle nutrients back to the soil; and Promote the growth of trees, wildflowers, and other plants; Both fires set deliberately and even some wildfires that are left to burn out naturally benefit natural resources and reduce the risk of unwanted wildfires in the future. Fire officials also use hand tools and machines to thin overgrown sites in preparation for the eventual return of fire. The significant downside to prescribed fires is that the smoke released by any type of fire (forest, brush, crop, structure, tires, waste or wood burning) is a mixture of particles and chemicals produced by incomplete burning of carbon-containing materials. All smoke contains carbon monoxide, carbon dioxide and particulate matter (PM or soot). Smoke can contain many different chemicals, including aldehydes, acid gases, sulfur dioxide, nitrogen oxides, polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, styrene, metals and dioxins. The type and amount of particles and chemicals in smoke varies depending on what is burning, how much oxygen is available, and the burn temperature. Exposure to high levels of smoke should be avoided. Individuals are advised to limit their physical exertion if exposure to high levels of smoke cannot be avoided. Individuals with cardiovascular or respiratory conditions (e.g., asthma), fetuses, infants, young children, and the elderly may be more vulnerable to the health effects of smoke exposure. view more
Credit: NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team. Caption: NASA/Goddard, Lynn Jenner with information from the Queensland Government Rural Fire Service