Congratulations to Gabriel Kooperman on his recent move to University of Georgia for a position as an Assistant Professor in the Department of Geography! Gabe was a postdoctoral scholar at UCI, first in the laboratory of Michael Pritchard, and then with James Randerson. Gabe studies the influence of climate change on weather extremes using global climate models. He is an expert in understanding how the intensity and frequency of precipitation will change in response to rising levels of atmospheric carbon dioxide.
In a paper published this week as a research article in the journal Science, Niels Andela and coauthors show that global burned has declined by nearly a quarter over the past two decades. The loss of fire was greatest in savanna and grassland ecosystems across northern Africa, the Eurasian steppe, Latin and South America, and some areas of Southeast Asia and Australia. Taking fire as an indicator of ecosystem health, the rapid decline in burning points to a profound, human-driven transformation of savanna and grassland ecosystems over the past 20 years. The authors show that significant increases in population, livestock density and cropland areas are important contributors to the decline in fire activity, and that the changes in fire are modifying atmospheric composition and ecosystem structure. State-of-the-art prognostic fire models could not reproduce the magnitude of the declining trends, suggesting that more research is needed to understand how land use change modified fire dynamics. Niels is a UCI postdoctoral scholar and NASA research scientist who works at Goddard Space Flight Center. He is co-advised by Douglas Morton and Jim Randerson. News reports about the study include articles in the Washington Post and Popular Science. NASA and UC Irvine released additional information about the study.
Figure caption: Expansion of crop production has fragmented many savanna landscapes, restricting fires to remaining patches of natural vegetation. This false-color Landsat8 image from the Brazilian Cerrado shows an actively burning fire in a fragment of remaining savanna vegetation, surrounded by agricultural fields. Fire scars from other recent burns appear maroon (Douglas Morton, NASA).
The study was funded by the Gordon and Betty Moore Foundation, NASA, and other sources. The data we used in the study can be found at:
In a paper published in Nature Climate Change this week, Sander Veraverbeke from the Vrije University in the Netherlands found that lightning ignitions were responsible for a record number of fires in the Northwest Territories and Alaska during 2014 and 2015. A unique feature of these fire extremes was their close proximity to northern treeline. Sander was also able to demonstrate that lightning ignitions were linked to summer temperatures over the past decade, and that lightning explained a considerable amount of the year-to-year variability in burned area and fire emissions in these regions. Although it has been well recognized that warmer temperatures increase the amount of burning and also likely increase the severity of fires, the link between climate and lightning was a novel element of Sander’s study. The study also describes the potential for a positive feedback loop in which climate warming allows lightning to move farther north, sparking fires in arctic tundra. An increase in arctic fire, in turn, may allow trees to migrate northward faster, which will further enhance atmospheric heating and lightning ignition in a positive feedback loop. This amplification loop is important because arctic tundra covers vast reservoirs of permafrost carbon that may become vulnerable once fires consume moss layers on the surface that act to insulate frozen carbon from climate warming. Coverage on the study included news reports in Scientific American and National Geographic. Sander is a former UCI project scientist, and co-authors on the study include UCI Ph.D. student Elizabeth Wiggins and former Ph.D. student Brendan Rogers.
Elizabeth Wiggins received a best student poster award for her work on “Environmental Controls on Wildfire Emission Factors in Alaska during 2015.” Liz was able to show that emission factors for carbon monoxide and methane from boreal forest fires may be higher than previous estimates because of significant emissions during night time periods with smoldering combustion. In her analysis, Wiggins combined continuous time series measurements of CO2, CO, and CH4 from a tall tower in Alaska with an atmospheric model. The use of the atmospheric model allowed her to estimate the back trajectory and origin of trace gas signals measured at the tower. Congratulations to Liz!
Morgan Gorris was awarded a best student presentation award by the American Meteorological Society (AMS) for her talk on “The Spatiotemporal relationship between climate and valley fever in the Southwestern United States.” Morgan presented her work at the 97th AMS meeting in Seattle in January. In her analysis, Morgan was able to document for the first time how climate and other environmental factors regulate valley fever incidence across different counties in California, Utah, Nevada, Arizona, and New Mexico. Her work shows that the primary valley fever hotspot has shifted from the Central Valley of California to Arizona. Congratulations to Morgan!