Interactive comment on “The sensitivity of Secondary Organic Aerosol component partitioning to the predictions of component properties: part 2; determination of particle hygroscopicity and its dependence on “apparent” volatility” by D. O. Topping et al
Interactive comment on “The sensitivity of Secondary Organic Aerosol component partitioning to the predictions of component properties: part 2; determination of particle hygroscopicity and its dependence on “apparent” volatility” by D. O. Topping et al
复制标题
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
D. O. Topping
中科院分区：
文献类型：
--
作者：
D. O. Topping
仔细检查他们的声明对先前实验室和现场吸湿性研究的影响。作者的讨论限制在第9030页，他们指出：“然而，在室实验中报告了使用多种仪器测量SOA颗粒吸湿性的差异，这可能归因于本文所述的效应（Good等人，2010;Duplissy等人，2009年），因为在富含硝酸盐的条件下未能实现封闭归因于HTDMA蒸发半挥发物”。具体而言，我认为，作者们必须对“可归因于本文所述影响的”这一短语加以扩展。根据他们对效果的描述，根据在整个实验中保持平衡分配的可能性对技术进行分类可能很重要。例如，使用HTDMA方法的测量可能被预期对EDB测量不同程度的重新划分敏感。在后者中，连续冲洗的湿/干氮气的气相分配将是不可逆的，而使用前一种方法进行的测量可能在某种程度上允许再分配是可逆的。在这种情况下，据推测，报告的GF可能仅包括在较高RH下按质量分配到冷凝相中的较大分配的固有校正因子。
closely examine the consequences of their claims for previous laboratory and field studies of hygroscopicity. The limit of discussion by the authors is on page 9030 when they state: “However, discrepancies in measurements of SOA particle hygroscopicity with multiple instruments have been reported in chamber experiments that could be attributable to effects such as those described here (Good et al., 2010;Duplissy et al., 2009), as has failure to achieve closure under nitrate rich conditions attributed to HTDMA evaporation of semi-volatiles”. Specifically, I think it is important that the authors expand on the phrase “that could be attributable to effects such as those described here”. Based on their description of the effect, it may be important to classify techniques according to how likely the equilibrium partitioning is to be maintained throughout the experiment. For example, measurements using a HTDMA approach might be expected to be susceptible to repartitioning to a different degree to EDB measurements. In the latter, the partitioning into a gas phase of continually flushed wet/dry nitrogen will be irreversible whereas measurements made using the former approach may, to some extent, allow the repartitioning to be reversible. In this case, the reported GFs could, presumably, just include an inherent correction factor for the greater partitioning by mass into the condensed phase at higher RH.