【摘要】 羟基（OH）自由基作为大气中关键的氧化剂，在调控大气化学成分、影响空气质量及气候变化中发挥着重要作用。准确评估全球OH浓度水平及其演变趋势，对理解大气化学过程、评估环境与气候态势至关重要。本文系统梳理了全球OH浓度和趋势评估指标，汇总了当前研究对全球OH的定量方法，包括地基指示剂观测反演、正向模式模拟、基于卫星数据等评估方法。现有对OH浓度趋势的研究表明，地基指示剂观测反演方法与正向模式模拟在长期趋势上存在分歧，不同研究使用指示剂反演方法的结果并不一致，而模式研究结果表明OH浓度在1980年后呈上升趋势；卫星方法对OH评估的不确定性仍然较大，有待进一步发展。未来，需要进一步加强指示剂和前体物的相关观测，为OH评估提供更多的观测约束，同时进一步发展新的指示剂、优化模式机制、拓展新的评估方法，以提升全球OH评估的准确性与可信度。更多还原

【Abstract】 Hydroxyl(OH) radicals, as key oxidants in the atmosphere, play a critical role in regulating atmospheric chemical composition and influencing both air quality and climate change. Accurately assessing the global OH concentration levels and trends is essential for understanding atmospheric chemical processes and evaluating environmental and climate conditions. This paper systematically reviews the global OH evaluation indicators, and summarizes the current quantitative methods for global OH in research, including inversion of ground-based indicator observation, model simulations, and satellite-based evaluation methods. Existing research on OH concentration trends reveal discrepancies between ground-based indicator inversion methods and forward model simulations regarding long-term trends. Results from indicator inversion methodsvary across studies, while model-based studies suggest an increasing trend in OH concentrations after 1980. Satellite methods still exhibit significant uncertainties in OH assessment and require further development. In the future, it is necessary to further strengthen the relevant observations of indicators and precursors to provide more observational constraints for OH assessment. At the same time, it is essential to further develop new indicators, optimize atmospheric chemical model mechanisms, and explore new assessment methods to improve the accuracy and reliability of global OH assessment.更多还原