Abstract: To explore the temporal and spatial variations of biogenic volatile organic compound (BVOCs) emissions, based on the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover dataset, the meteorological model WRF and BVOC emissions estimation model MEGANv3.2 were used to simulate the BVOC emissions in China in 2020. The maximum incremental reactivity method and the fractional aerosol coefficient method were used to quantify the impacts of BVOC emissions on ozone (O₃) and secondary organic aerosol (SOA) formation. The results showed that the total BVOC emissions in China in 2020 was 29.16 Tg, with isoprene, monoterpenes, sesquiterpenes, and other VOCs (OVOCs) accounting for 27.54%, 22.29%, 3.16%, and 47.05% of the total annual emissions of BVOC, respectively. In terms of temporal distribution, BVOC emissions in spring, summer, fall, and winter accounted for 17.49%, 63.68%, 16.12%, and 2.71% of the total emissions, respectively. In terms of spatial distribution, BVOC emissions generally showed a trend of high in the southeast and low in the northwest, with the Guangxi Zhuang Autonomous Region, Guangdong Province, and Hunan Province having the highest BVOCs emissions, accounting for 11.08%, 8.06%, and 8.02% of the total emissions. The total O₃ formation potential (OFP) and SOA formation potential (SOAP) of BVOC emissions in 2020 were 175.17 and 2.60 Tg, respectively, with isoprene being the main source of OFP, accounting for 48.63% of the total OFP, and monoterpenes being the main contributor to SOAP, accounting for 74.90% of the total SOAP.

Key words: volatile organic compound (VOC), emission inventory, O₃, secondary organic aerosol (SOA)