Li Qinyi, Tham Yee Jun, Fernandez Rafael P, He Xu-Cheng, Cuevas Carlos A, Saiz-Lopez Alfonso
Department of Atmospheric Chemistry and Climate Institute of Physical Chemistry Rocasolano, CSIC Madrid Spain.
School of Marine Sciences Sun Yat-Sen University Zhuhai China.
Geophys Res Lett. 2022 Mar 28;49(6):e2021GL097567. doi: 10.1029/2021GL097567. Epub 2022 Mar 14.
Heterogeneous uptake of hypoiodous acid (HOI), the dominant inorganic iodine species in the marine boundary layer (MBL), on sea-salt aerosol (SSA) to form iodine monobromide and iodine monochloride has been adopted in models with assumed efficiency. Recently, field measurements have reported a much faster rate of this recycling process than previously assumed in models. Here, we conduct global model simulations to quantify the range of effects of iodine recycling within the MBL, using Conventional, Updated, and Upper-limit coefficients. When considering the Updated coefficient, iodine recycling significantly enhances gaseous inorganic iodine abundance (∼40%), increases halogen atom production rates (∼40% in I, >100% in Br, and ∼60% in Cl), and reduces oxidant levels (-7% in O, -2% in OH, and -4% in HO) compared to the simulation without the process. We appeal for further direct measurements of iodine species, laboratory experiments on the controlling factors, and multiscale simulations of iodine heterogeneous recycling.
次碘酸（HOI）是海洋边界层（MBL）中主要的无机碘物种，它在海盐气溶胶（SSA）上的非均相吸收形成一溴化碘和一氯化碘，已在模型中以假定效率被采用。最近，实地测量报告称，这一循环过程的速率比模型先前假定的要快得多。在此，我们进行全球模型模拟，以使用常规、更新和上限系数来量化MBL内碘循环的影响范围。考虑更新系数时，与不进行该过程的模拟相比，碘循环显著提高了气态无机碘丰度（约40%），增加了卤素原子生成率（碘约40%，溴>100%，氯约60%），并降低了氧化剂水平（O降低7%，OH降低2%，HO降低4%）。我们呼吁进一步对碘物种进行直接测量、开展关于控制因素的实验室实验以及对碘非均相循环进行多尺度模拟。
