Climate change decreases the cooling effect from postfire albedo in boreal North America.

Autor: Potter S; Woods Hole Research Center, Falmouth, MA, USA., Solvik K; Woods Hole Research Center, Falmouth, MA, USA.; Geography Department, University of Colorado, Boulder, CO, USA., Erb A; School for the Environment, University of Massachusetts Boston, Boston, MA, USA., Goetz SJ; School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA., Johnstone JF; UAF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AL, USA., Mack MC; Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA., Randerson JT; Department of Earth System Science, University of California, Irvine, CA, USA., Román MO; Earth from Space Institute, Universities Space Research Association, Columbia, MD, USA., Schaaf CL; School for the Environment, University of Massachusetts Boston, Boston, MA, USA., Turetsky MR; Department of Integrative Biology, University of Guelph, Guelph, ON, Canada., Veraverbeke S; Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands., Walker XJ; Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA., Wang Z; Earth from Space Institute, Universities Space Research Association, Columbia, MD, USA.; Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA., Massey R; School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA., Rogers BM; Woods Hole Research Center, Falmouth, MA, USA.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2020 Mar; Vol. 26 (3), pp. 1592-1607. Date of Electronic Publication: 2019 Nov 19.
DOI: 10.1111/gcb.14888
Abstrakt: Fire is a primary disturbance in boreal forests and generates both positive and negative climate forcings. The influence of fire on surface albedo is a predominantly negative forcing in boreal forests, and one of the strongest overall, due to increased snow exposure in the winter and spring months. Albedo forcings are spatially and temporally heterogeneous and depend on a variety of factors related to soils, topography, climate, land cover/vegetation type, successional dynamics, time since fire, season, and fire severity. However, how these variables interact to influence albedo is not well understood, and quantifying these relationships and predicting postfire albedo becomes increasingly important as the climate changes and management frameworks evolve to consider climate impacts. Here we developed a MODIS-derived 'blue sky' albedo product and a novel machine learning modeling framework to predict fire-driven changes in albedo under historical and future climate scenarios across boreal North America. Converted to radiative forcing (RF), we estimated that fires generate an annual mean cooling of -1.77 ± 1.35 W/m 2 from albedo under historical climate conditions (1971-2000) integrated over 70 years postfire. Increasing postfire albedo along a south-north climatic gradient was offset by a nearly opposite gradient in solar insolation, such that large-scale spatial patterns in RF were minimal. Our models suggest that climate change will lead to decreases in mean annual postfire albedo, and hence a decreasing strength of the negative RF, a trend dominated by decreased snow cover in spring months. Considering the range of future climate scenarios and model uncertainties, we estimate that for fires burning in the current era (2016) the cooling effect from long-term postfire albedo will be reduced by 15%-28% due to climate change.
(© 2019 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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