edu.ucar.opensky::articles:26367 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T19:32:19.414157 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7fj2ms6 https://doi.org/10.5065/D6WD3XH5 https Related Software #1 NCAR Command Language (NCL) Exploring the factors controlling the long-term trend (1988–2019) of surface organic aerosols in the continental United States by simulations 2023-05-16T00:00:00Z publication https://n2t.org/ark:/85065/d7fj2ms6 https://doi.org/10.1029/2022JD037935 Liu, Y. author Dong, X. author Emmons, Louisa K. author Jo, Duseong author Liu, Y. author Shrivastava, M. author Yue, M. author Liang, Y. author Song, Z. author He, X. author Wang, M. author UCAR/NCAR - Library publisher Observed surface organic aerosols (OA) concentrations slightly increased in the western US (WUS) but significantly decreased in the eastern US (EUS) in summer, and continuously decreased in winter over the US region. To understand the driving factors for the long-term surface OA trend, we apply a revised version of the Community Atmosphere Model version 6 with comprehensive tropospheric and stratospheric chemistry representation, considering the heterogeneous formation of isoprene-epoxydiol-derived secondary organic aerosols (SOAIE) and fast photolysis rate of monoterpene-derived secondary organic aerosols (MTSOA) to diagnose the OA evolution in 1988-2019. Compared to older versions, the revised model better reproduces the climatology, seasonal cycle, and long-term trend of surface OA as evaluated against the Interagency Monitoring of Protected Visual Environments measurements. We find the decrease in EUS summertime OA is likely attributed to the interplay between SOAIE and MTSOA. With anthropogenic emissions reduction, primary organic aerosols (POA) declined, SOAIE decreased along with sulfate, while MTSOA increased along with biogenic emissions driven by a warming climate. POA from wildfires with a significant trend of 2.9% yr(-1) and considerable interannual variation of 62.8% drive the statistically insignificant but increasing WUS summertime OA, while anthropogenic POA dominates the decreasing wintertime OA in the US. Through sensitivity experiments, we find MTSOA show linear responses to the increasing monoterpenes emissions and negligible responses to NOx emissions reduction due to the mutual offsets between MTSOA components from different oxidation pathways. This study reveals the increasingly important role of MTSOA in summertime OA under a warming climate. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2023 American Geophysical Union (AGU). None eng geoscientificInformation