North-south antiphase of wildfire activity across the pyroregions of continental China driven by NAO and the Antarctic oscillation

Abstract

Wildfires are a natural disturbance in many parts of the world, but fire regimes are changing as a result of anthropogenic pressures. A key uncertainty towards anticipating future changes in burned area lies in understanding the effects of climate teleconnections (CTs). Here we test how different CTs impact burned area in China, a large country comprising different biomes and where similar fire-suppression and post-fire afforestation policies are implemented. We observed diverging temporal trends in burned area across the different pyroregions of China, from increases in the Northeastern grasslands and mixed forests pyroregion to decreases in the Southern tropical forests pyroregion. This North-South antiphase in fire activity was being partly driven by joint effects of the North Atlantic Oscillation and the Antarctic Oscillation, which exerted contrasting effects on fire weather across latitude. El Niño Southern Oscillation and the other examined teleconnections had minor effects over burned area. The increasing burned area in the NE-mixed forests pyroregion indicates that mega-fires may increase under global warming but their occurrence may be modulated by potential strengthening or weakening of NAO and AAO.

This work was supported by the National Natural Science Foundation of China (U20A20179, 31850410483), the Talent Proposals in Sichuan Province (2020JDRC0065) and by Southwest University of Science and Technology (18ZX7131). We remain indebted to the critical comments from two anonymous reviewers and the editor.